Apr 2021 – David Virshup & Judith Eisen

On Stem Cells and Neurodevelopment In the Gut

Dr. David Virshup is the director of the Programme of Cancer and Stem Cell Biology at Duke-NUS Medical School as well as a professor of pediatrics at Duke University. He Received his MD from Johns Hopkins, followed by a residency in Pediatrics and a fellowship in Pediatric Hematology/Oncology. He established his independent laboratory at the University of Utah, where he was an endowed chair at the Huntsman Cancer Institute. In 2007, he moved to Duke-NUS in Singapore to help establish the Cancer and Stem Cell Biology programme. He is Elected to the: American Association for the Advancement of Science and the Association of American Physicians. His research focused on signal transduction, with an emphasis on both Wnt signaling and circadian rhythms, and his laboratory has collaborated to develop a small molecule inhibitor of Wnt secretion that is now being tested in human clinical trials.

Dr. Judith Eisen is a Professor in the Institute of Neuroscience at the University of Oregon. She completed her PhD in neurobiology from Brandeis University where she worked  in the lab of Eve Marder, where she studied circuit neuromodulation in the stomatogastric ganglion. She later joined the laboratory of Dr. Monte Westerfield at the University of Oregon as his first post-doc, where she developed methods to label and track individual neuron progenitors in the zebrafish. She then was hired by the University of Oregon as faculty, and her lab has been focused on studying how neuronal diversity is generating during development, how these neuronal circuits are wired up and how host-associated microbiota and immune systems work together to influence the development of the nervous system. Dr. Eisen has authored over 150 publications, has been awarded the Gugenhein Memorial Foundation Fellowship, and is both a fellow of the Association for the Advancement of Science and the American Academy of the Arts & Sciences. 

Mar 2021 – Lori Zeltser & Alexandre Caron

The Chilling Side of Hunger

Dr. Zeltser is an Associate Professor in the Naomi Berrie Diabetes Center and the Department of Pathology and Cell Biology at Columbia University. she graduated from Princeton University and received her Ph.D. from The Rockefeller University. She continued her research training in developmental neurobiology and did her postdoctoral fellowship in the laboratories of Andrew Lumsden at Kings College London and Claudio Stern and Thomas Jessell at Columbia University. Currently, Her laboratory studies developmental influences on the formation and function of neuronal circuits regulating food intake and body weight, they explore how developmental influences exert lasting impacts on body weight regulation. 

Dr. Caron is an Assistant Professor at Laval University. He completed his PhD at Laval University with Drs. Denis Richard & Dr. Mathieu Laplante where he studied how an mTOR interacfting protein was involved in energy balance. He completed his post-doc at UTSW with Dr. Joel Elmquist, where he focused his efforts into studying how leptin is produced and where it functions through pharmacogenetics and transgenic approaches. His lab’s current goals are to understand the mechanisms by which the brain controls energy metabolism and develop pharmacological strategies to treat metabolic diseases and disorders.

Feb 2021 – Nicholas Betley & Daniel Drucker

Sensing Nutrients, Secreting Peptides

Dr. Betley received his Ph.D.,from  Columbia University, in 2010, where he worked with Thomas Jessell and investigated the developmental programs that determine synaptic partners during circuit formation. For his post doc he worked in Janelia Research Campus with Scott Sternson where they examined the structure and function of neural circuits that influence feeding behaviors.currently he is an Assistant Professor of Biology at the University of Pennsylvania. His lab is interested in understanding how the brain processes information from the external world to facilitate appropriate behavioral responses that are necessary for survival. 

Dr. Drucker is an Endocrinologist and Professor of Medicine in the Division of Endocrinology at the University or Toronto. He was trained in Internal Medicine and Endocrinology at the Johns Hopkins Hospital in Baltimore and the Toronto General Hospital, University of Toronto and completed a research fellowship in Molecular Endocrinology (1984-87) at the Massachusetts General Hospital. He has conducted pioneering work that has furthered our understanding of glucagon and GLP-1 and has authored several hundred publications, and issued 33 US patents covering various novel therapeutic aspects of peptide hormone action.

Episode 18: Our Greatest Challenge

Peter 0:13
Hi, and welcome back to the Gastronauts Podcast. My name is Peter and I’ll be your host. As many of you know, here at Gastronauts, we are committed to exploring communication throughout the body, with a particular focus on the crosstalk between gut and brain. We invite speakers across the globe to share both their research and their life journeys. So come join me as we explore the steps that go into shaping a scientist on the Gastronauts Podcast.

Today, we have a panel of four incredible rising stars in their respective fields. Dr. Kara Marshall is a postdoctoral fellow at Scripps Research in San Diego, California. She studies the nerves that control our bladder. And recently she found out that Piezo2, a molecular channel that senses mechanical forces, in fact works to control our peeing.

Dr. Kara Marshall 1:23
Thanks.

Peter 1:24
Dr. Dafni Hadjieconomou is a postdoctoral fellow at the Imperial College of London. She studies how neural circuits in the gut of a fly, or these enteric neurons, are altered during pregnancy. And she has found that these enteric neurons are key to increasing food intake of the mother and enhancing reproductive success.

Dr. Dafni Hadjieconomou 1:45
Thank you.

Peter 1:46
Dr. Marcelo Zimmer is a postdoctoral fellow at Yale and the Federal University of Rio. He studies how certain neurons in the brain of a neonatal mouse respond to maternal separation. Activation of these neurons induces ultrasonic vocalizations or USVs to encourage the mother to return to the pup, so she can continue providing care.

Dr. Marcelo Zimmer 2:08
Thank you.

Peter 2:09
And lastly, Dr. Yuuki Obata, is a postdoctoral fellow at the Crick Institute of London. He studies how bacteria in our gut talk to neurons in our gut to change intestinal motility and control the rate at which food moves through our intestinal tract.

Dr. Yuuki Obata 2:25
Thank you.

Peter 2:26
Science is a global endeavor, and we can tell from this conference with people calling in from all over the world. It’s really great seeing so many excited and engaged scientists, but it has to start small- from the groups with the people that you work with, with the mentorship that you provide different people who are just, you know, trying their first time in science. Now that you all are transitioning from the postdoc to perhaps an independent investigator, what mentoring principles Do you guys hold? Or what are you looking for in a trainee?

Dr. Kara Marshall 2:56
I mean, I’ll start I mean, I’m not a PI yet. But I actually think about it a lot. Because this is the huge jump that we have to make, right? We go from being bench scientists to all of a sudden being mentors, and it’s a completely different job. So I think about it a lot now to be like, how can I prepare and do a good job. And I think that one of the things that I’ve learned the most is that, you know, just like anything else, it is a skill. And unfortunately, I think a lot of people don’t consider that as you know, a skill that they can build and should try to build. And like, there is known information out there about how to be a good manager, and scientists are not concerned with that, right? Because we’re all excited about the science. And so we all focus on just like let’s get the science done. But um, yeah, as a PI, like, you have to manage people, that’s kind of your number one job. And so I think that, you know, I was talking to someone not too long ago about how she actually just hired someone in the business world to teach her how to hire people, and how to manage people, because it’s like, these are not unknown things, and scientists just kind of like, wing it, you know, and ends up being it ends up making for really, sometimes unprofessional environments, and then also environments where really, people aren’t doing their best science because they don’t feel like they’re being managed appropriately. And so I don’t know, I guess just having a growth mindset. That’s kind of cheesy, but it’s true, right? Like, you can learn these things like there’s, you know, data out there. And so trying to actually just learn the skills that are needed to manage people, I think, and just listening to people and actually really listening to what each individual needs and not just trying to one, one fits all solution. That’s my goal.

Dr. Dafni Hadjieconomou 4:29
Yeah, I would really also second that, I guess, for me, with a little bit of mentorship that I have given and what I have experienced, I think this the you should never think that one fits all is the take home message for me. You know, because I have also tried to be the mentor I wanted but this doesn’t always work. So I guess it’s going to be a lot of trial and error and there will be biases, you know, for for the mentor you wanted to have always or you had and you really loved or you had an you really hated. And I guess this is why what you’re saying care there is is important, perhaps we have to really work on this as a muscle that has to grow actively. And I guess also, again, get information as we do with everything else get information from people that have done it a while back. And we respect for instance, I guess this is how I plan to do it.

Dr. Marcelo Zimmer 5:25
Yeah, I definitely agree with Dafni, I think we need to learn from people who are already in the lab mentoring people, because as Kara said, we don’t know how to manage people, and then we suddenly we are being mentored to mentor people. So it’s a rapid transition. As a mentor, if I’ll be a mentor, one day, I’ll try to use my experience during my PhD, to do the same that I that I received while I was a practitioner to the students. And I think one of the best ways to do science is being always highly motivated. You need to motivate your students, we know that motivation plays a critical role in continuing science, because we’re going to fail all the time, failure will be a part of the process during our studies. So I think having a highly motivated mentor, they allow us to do anything that you wanted. I think that is the key, in my opinion.

Dr. Yuuki Obata 6:18
Yeah, I think I was very lucky to have great mentors. So what I learn from them in my future career. And also I have experience to teach some students in the lab, and they’re also great, and they really like science and think about trying to addressing the question not just for the job. So then the very good relationship was built. So yeah, that’s I think that depends on the motivation, the science and yeah.

Peter 7:02
We have a question from Lihua.

Audience 7:04
Dr. Zimmer, my question is: early life isolation that used in your model, your mouse model have been known to induce irritable bowel syndrome in the mouse. I’m just conscious curious, like, whether you finding has anything that related to the symptoms that developed in mouse models later in their life, like, increase of visceral sensitivity, and difference in the enteric motility and whether you’re finding will have anything connection to that

Dr. Marcelo Zimmer 7:39
Thanks for the great question. It’s something that people usually ask for us, if you follow the facts of the material separation later in life, and we never follow actually. So I don’t know. I don’t know if they actually they could be contributing for the development of the irritable bowel syndrome, but it’s definitely like at a very important question to try to evaluate the future for sure. Thanks for the question.

Peter 8:04
Next, we have Julia Davis.

Audience 8:06
I’m calling him from Boston. And I just had kind of like a more general question. Earlier this week, I was just looking at some literature and kind of like the gut brain axis and its relationship with neuro-inflammation. And I was wondering, like, if any of you kind of have thoughts on that, or like the mechanisms for how that might influence other disorders like delirium, or Alzheimer’s disease, which are often linked to neuro inflammation, and just kind of like, if you think that there is kind of value in going down that path, and seeing if there’s the microbiome does can play a role in our understanding of those diseases that are still kind of a little bit unclear.

Dr. Dafni Hadjieconomou 8:41
I think it’s pretty exciting. And I guess we don’t have the tools perhaps, or the understanding yet on how this works exactly. But, you know, and this is what I sort of wanted to put out there with my introductory bit that is so complicated, because we just beginning to understand that this microbiome does a lot of very different things. And, you know, Yuuki presented one of these aspects, but I guess it’s out there that this is all regulated and there is a link for sure with with the brain, and then all of these disorders could be coming from the microbiome, and then they are linked directly to the brain or their local inflammation in the gut that then link looks back to the brain. And I guess all of them could have a little bit of that. And something we don’t quite understand yet. But sure, sure. Is it an exciting way forward to think about that?

Audience 9:43
Hey, everyone, my name is Maya Kaelberer. I’m at Duke University. So my question is actually for Dafni, and Yuuki: how’s the microbiome changing during pregnancy? And is it known if these changes are actually affected some of the food intake right so I’m assuming that pregnancy does a lot to the body. I’m just wondering does it change the microbiome? And can you actually change your food intake that way?

Dr. Dafni Hadjieconomou 10:06
Thank you. I think I’m gonna let Yuuki go first. I’m not a microbiome expert.

Dr. Yuuki Obata 10:13
I’m not sure about this. And we know maternal microbiota is very important for the development of the immune system and nervous system have in the offspring animal. But in this case, I’m not sure how pregnancy affected it. I can imagine there are many changes to hormonal change can affect the microbiome, but I don’t know.

Dr. Dafni Hadjieconomou 10:33
And if we take it back to the fly, I guess there there are differences in general, with the microbiome and the colonization, and so on, as surely when flies lay eggs, they do also lay a bit of anti-microbials. So there might be changes. Sure. We don’t know if these do affect the way the flies eat? Not to my knowledge. I don’t know that. But yeah, very interesting question, Maya, for sure.

Peter 11:08
Yeah, I think it’s a really great question. And it made me think of, I guess, technological developments, and how we think about technology changing over time, and a lot of our studies are done really at a specific time point, or at a specific location, right? How do you expect your findings to translate across time or at different stages during development? I think each one of our talks today had a little bit of this theme, right? With Marcelo’s Agrp neurons having a different function early on in life. Dafni during reproduction, you have, you know, this innervation that has a differential effect. And Kara, right, when you mentioned, specifically like these Piezo2 neurons and piezo and urinary issues happened primarily when we’re older. So I was curious as to, just to reiterate, like how you expect the findings that you have to translate across different times? Or is this something that you’re interested in moving forward?

Dr. Dafni Hadjieconomou 11:57
Yeah, absolutely. I think, you know, this audience is already already unique, that, you know, we do think of other bits of the other organs, not only one, like people normally really focus on one neuron in the brain or one year, in their favorite place, or, and here, we’re talking about inter organ signaling. But I think also, yes, absolutely. For me, the timing is a very important element, because we you look at this ms neuron that I described, and it’s very different after mating, animated female. And I have also seen that it’s, it’s quite different after different food in food to being presented with different dietary challenges, let’s say. So this is also what I plan to do, I plan to see what happens in different challenges internally, but also in different times. So developmental is one thing, and how that shapes its function in the adult, for instance, because now what I presented, you were specifically adult neurons, right, that were manipulated for a few hours in the adult body. And that’s the beauty again, of the fly. But you can do the manipulation the other way around and look later on what happens. So for me, absolutely.

Dr. Marcelo Zimmer 13:14
I think that one of the biggest reasons that I’m doing this research in infants is trying to understand how the new secrets which neural secrets involve, and which neural secrets regulating behavior, because what we know from the literature is that any type of early life stress in an infant, and we’re talking about many types of mammals, including humans, leads to long term consequences. So if you at least start to tracking which are the newest they are, they are sensitive, when the animals are isolated with animals are exposed by like stress, we can actually benefit us understand if the neighbors were involved in this long term consequences that we see when we isolate all the animal is exposed to like stress.

Dr. Yuuki Obata 13:58
Yes, time is a very important factor for for our system as well. Actually, we are recently interested in the effects of the time of the day in the in the physiology of the enteric nervous system. As you can imagine, it’s it has a circadian rhythm in the activity of chronic peristalsis. And also, the number and composition of microbiota shows circadian rhythm as well. So we we are actually interested in how changing their time affect the physiology. Of course, we also are interested in the developmental time period or embryonic stage. This is a very important topic to study.

Dr. Kara Marshall 14:44
Yeah, I kind of touched on it. I totally agree that given the role of aging and kind of how aging ends up corresponding with a lot of issues in the urinary tract, it’ll be interesting to see how these circuits change how the sensors change, and then Development here. I mean, both sides of the equation are really fascinating.

Audience 15:02
Hi, hello, I’m Elaine Snell, I’m from London, does Piezo2 naturally diminish with age? And in which case, does that explain the high rate of urinary dysfunction in people of an older age group? And would that be or is it already a target for for treatment or strategy for treatment to kind of replace that if that’s possible?

Dr. Kara Marshall 15:25
Excellent question. And it’s something that I can’t answer directly, because we don’t know if the protein expression changes during age in the system. But I’ll answer it from the perspective of what we know about the skin because we know a lot more about touch receptors in the skin, which are also mechano-sensitive. And we do know that with age people do lose these sensory neurons. So your innervation, density goes down, and you become less touch sensitive. And so it’s very possible that this happens internally as well. And again, I think that this is an entire area that could be really interesting to understand how internal innovation changes with age, and maybe it’s diminished in the same way that our skin innovation has diminished. And all of the sequela that come after that, right? You know, neuropathy, diabetic neuropathy, which of course, diabetes is very common, and that leads to degeneration of some of these, some of these innervation. And it could have, you know, similar effects in the skin as it does inside, so you might get all of the reflexes, all of the sensing, if that’s gone, you know, that could absolutely cause dysfunction. And so I don’t know yet, but there’s definitely a precedent for that in other organs. So it’d be interesting to see. And then as far as therapeutics, you know, I’m a big believer and understanding the basic science and molecules of how things work, give us targets. Right now, we don’t have good pharmacological tools to target this ion channel, in particular. It’s proving to be actually quite difficult, because unlike a lot of other ion channels, these respond to tension in the membrane. And so how do you make a drug that targets that- it’s not clear that we’re going to have great like a lock and key mechanism where we can get something to bind. And so that hasn’t been very easy to find so far. In the future, though, it would be wonderful if it could, because I sort of touched on in the beginning that this, this protein is involved in so many different sensory functions. And so it would be great to have a pharmacological tool. But you know, if not pharmacological, you know, maybe there’ll be something else, some sort of genetic tool, or even estimate stimulation protocols, or something that we could do to help in the future. It’d be really interesting.

Peter 17:21
Next, we have a question from Valentina.

Audience 17:24
I’m calling in from Boston. And I have a question for Kara. I was wondering if you looked at the role of sex hormones in your model. And if you think, or if you observed any differences in your knockouts between males and females. I guess I’m just wondering if sex hormones might potentially regulate Piezo2 and these different patterns for urination?

Dr. Kara Marshall 17:47
Yeah, that’s interesting. So I haven’t looked at this at all. But it’s an interesting question, because we do know that some of these lower urinary tract pathologies are very different between men and women in terms of what kinds of pathologies they get, and how they manifest. And part of this is simply anatomical, males have much longer urethra. So they’re less prone to say UTIs but then there are other problems that come with having a prostate. And so part of these anatomical differences kind of designate what the pathologies are later in life. So I haven’t looked at sex hormones in particular, but it’s also possible that kind of overlaid on top of the anatomy has some role. But I don’t know the answer to that yet. I will say that I did do full cohorts of males and females in all of my studies. And to the extent to which the responses are slightly different because of the anatomy. All of the other phenotypes were exactly the same. So I saw the same deficits in males and females, they saw the same remodeling. But again, you know, males, because they have, especially in mice, their ureters are so small and so long, that the coordination is particularly important for them to go. So I think the remodeling was maybe worse for them. But overall, it seemed like the result was the same in males and females. Thanks for the question.

Peter 18:57
Yeah, that’s interesting, this sex difference question reminded me of some of the things that Dafni talked about with the MS neurons. And I was wondering, do the sensory neurons of urinary control change during pregnancy? Like what are the parallels between the enteric nervous system and the bladder?

Dr. Kara Marshall 19:11
Yeah, I’d say that it’s all open. You know, I don’t know, I hadn’t really considered looking during pregnancy. But of course, that is a- that is a time of like, massive change. So it’d be interesting to know if some of the innovation changes to I don’t know.

Dr. Dafni Hadjieconomou 19:25
Yeah, I don’t know. This is why I thought, you know, it would be very interesting to see if the neurons change or the epithelium changes with both of them, and what happens at the molecular level, because, you know, somehow this body needs to cope. it undergoes under increasing pressure. And I guess in the mouse model, you might have more or less pups, and that also might change. So I think it’s very exciting to just have a look. Yeah, and I would imagine that there are changes, but then yeah.

Dr. Kara Marshall 19:59
I also wonder how different it is between mice and humans, given that humans are upright, and so much of that gravitational pull has a huge effect. And in mice, I wonder if I’m being this direction means that that is different. And you know, the the two horn of the uterus, maybe they actually are spared some of the issues that humans go through. I don’t know, though, be interesting to find out.

Peter 20:21
This is really interesting. Moving on, we have another question for Dafni. So the fly mid gut is like the primary site for food digestion & absorption, what is known about neuronal innervation in the fly mid gut? How are the enteric neurons affecting intestinal motility? absorption?

Dr. Dafni Hadjieconomou 20:40
Yeah, thank you. So not a lot was known. And the truth is that not a lot is known. So in fact, Irine’s lab really did bring home this. So she was one of the founders, I guess, in it, and there are enteric neurons and the fly. And the paper, the first paper of the lab described some of this innovation in our paper, the recent paper also gives a bit more information about the integration of the medical and especially the anteromedial, which is, I guess the question goes for that, where a lot of the digestion is happening now for the function. So we do know, for specific lineages, some of the aspects of the function that do go to the mid gut, and the neurons that I talked about today go to the mid gut, as well as the crop. And now for peristalsis, for the midgut. Specifically, I guess we don’t know exactly how they. So their motor, so the motor output is for specific types of neurons. If you talk completely paralyzed, of course, the gut. Yeah, there is a problem. But it’s just the beginning of this. So similar to the mammalian lineages, we did not we didn’t know so much about them, I guess, what is nice is that we can manipulate small subsystems of them and uncover what their function is.

Peter 22:05
Great- I actually had like a relatively broad question for all of you is really interesting seeing the different model systems that you all use. Marcelo, you mentioned that you’re planning to do some future work in guinea pigs, Dafni, you’ve been working flies; Kara, you’ve done some human studies, and Yuuki, you’re doing work in a nice. So I was wondering, how do you choose which animal system to use? And then in your future work do you plan on continuing to use the same animal models? Are you planning to diversify what systems you’re going to be studying?

Dr. Kara Marshall 22:32
I will say that it was actually a really fortunate thing that we were able to include the humans in the study with the mechanistic mouse models. And I think there was a bit of luck there, I mean, to have this group of patients was, we were incredibly fortunate because of course, you don’t always get that with any particular gene that you’re studying. So I would love to do more of that in the future. But I think it it sort of depends on, you know, wonderful collaborators, being open to open to working with us. And I think that that’s a general lesson in science, that if people are open to collaborating, especially across disciplines, like with clinicians, because of course, the science is very different, that the story becomes so much stronger. And so I mean, I would love it, if that could happen in the future again.

Dr. Dafni Hadjieconomou 23:13
I do plan to work on flies and, and actually collaborate or anything else. So my drive is really coming from basic discovery in basic science. So I think the fly is a powerful model for understanding genetics, and really basic mechanisms. And then the conservation of this, you know, other people that I can collaborate with can do in, in higher mammalian systems, let’s say that being the mouse or humans, for instance, I will be very excited to work with people along along the way. But my drive is really this basic mechanisms, and I plan to work on flies for the rest of it.

Dr. Marcelo Zimmer 23:57
I think, really the purpose of our long term goals. But I think as a scientist, we always try to contribute to the well being of the human being and to humans. But the reason I choose to move towards minipigs is that I’m really interested interested in the infant’s perspective of interaction with the mother. Whereas we know a lot of researchers in a lot of studies doing the maternal behavior in mice, right. So we don’t know much about how the infant’s they communicate how they how they interact the mother, most likely most because these infants they are born in a three show state, so they are really mature. So we cannot really evaluate the behavior of the infants during this first few days of life. Whereas the green epic the infant is born in precocious states, so the animals are much more active, much more mature. So using this animal model, I think we are able to at least understand better when do me think about your secrets that are involved in the infant direction to the mother.

Dr. Yuuki Obata 24:57
So for me, the reason I’m here using the mouse, so it’s just it’s very, very well organized, it’s very established model. But I’m also interested in the other other models, including a human, or even Hydra they, or zebrafish, because each each model has on advantage and disadvantage, a bad combination these studies helps us to understand different aspects of physiology by using different techniques.

Peter 25:28
Yeah, it’s really great to hear all of your perspectives on the pros and cons of different model systems, how sometimes it’s due to collaboration has sometimes it’s due to chance.

Audience 25:38
Hello, I’m yeah, I’m Alistair McDonald. And I’m calling from Exeter in the UK. And my question is for Dr. Marshall, I’m interested to know how much of the Piezo2 pressure sensing is, is mediating intrinsic kind of bladder or spinal to bladder versus integrating top down control from the brain. So you have some looks like full urination in the middle of the cage. So maybe properly initiated, but just at the wrong point, how much of that sensory detection is useful for the brain?

Dr. Kara Marshall 26:09
Yeah, so all of the functions I was showing with regard to cystometry and the urethral reflexes, these would be spinal reflexes, right? So these are mediated by spinal pathways. And, you know, we think the sensory neurons, of course, are directly conveying information, the bladder goes to the urethra, and the urethra actually goes to the bladder. So you know, you want when your bladder is ready to contract, you want it to contract against a relaxed urethra. And then similarly, when your rethrow has fluid flow go through, it sends signals back to increase bladder contraction. So these kind of are classical reflexes that have been defined for a while. So we think that definitely Piezo2 sensory neurons are mediating the initiation of these reflexes. But we haven’t looked at all as to you know, how this sensory information is integrated in Barrington’s nucleus, which is the nucleus that controls top down urination. And I’m so glad you brought it up, because it is really important. And in fact, people who study urination, primarily study these brain mechanisms that are critical for release of urination and of course, in humans and other animals. We have tight control over this and we don’t, you know, we only are supposed to go at appropriate times. And this is very important. And so I don’t know yet how Barrington’s integrates this information, but certainly it must right it It knows when your bladders full, and otherwise you don’t have that kind of urge. So yeah, I think it’d be really interesting to understand in the future, what those neurons are sensing.

Peter 27:51
We have a question from Jorge Villalobos.

Audience 27:54
Hey, I’m Jorge. I’m calling from Duke University. And I have a question for Dr. Zimmer. So Dr. Zimmer, what would happen if you play a recording of ultrasonic vocalizations on one side, then if you have a pup on the other side, would the ultrasonic vocalization would be like a stronger stimuli for the dam to prefer that side? Or would the olfactory cues from the pump would be a stronger signal and then the mother would go to the other side?

Dr. Marcelo Zimmer 28:23
Yeah, that’s a great question. We’ve never done this type of experiment, we try to evaluate whether only playing record user playback system in which we would play the record off of error mode in which we activate the newest compared to animal that is a control animal to see the model prefer one side over the other. And we are not capable of having like a final result, we realize that odor cues are super important. So not only visual cues, because once the mother realizes there is no neonates that are there she stopped, she stopped directing, but there are so we never done that. But if I have to guess I would say the daughter queues and this stage, they will play a higher role will be more important for a preference of the monitors, either the odor queues or the auditory cues.

Peter 29:14
Thank you. And we have another question from Amy Shepard.

Audience 29:18
Yeah, hi, I’m calling from Boston. And my question is for doctors around the USVs. I was wondering if not only does the number of calls change, but just the quality or complexity of those calls change. I’m only really familiar about USVs in adults, which I know have, you know, like a lot of variation. I wonder if you looked at that and those parts as well.

Dr. Marcelo Zimmer 29:38
That is a great question. Yes, we look at and indeed change change the part of the cause the animals they elicit different types of syllables. So in neonates, the list of 11 types of syllables that we know and when we quantify the number of vocalizations, in which syllables we find their activation of these neurons, the indeed increase some of the syllables One that we found was a channel was it was a charity organization. So we are trying to identify whether this has any meaning for the mother and look and talk about the spectral temporal features of the vocalizations, it does have a decrease in the duration, it seems to lead to change the new frequency distribution. So, yes, there’s a change.

Peter 30:20
Thanks for the question on communication, like USVs are ways neonates communicate, and I was wondering, you know, broadly about communication. We don’t communicate with USVs. So I was wondering, how do you think about communicating your work to fields very disparate from your own? How do you think about communicating to form collaborations and communication in general to inform the general public?

Dr. Marcelo Zimmer 30:42
Yeah, that’s not an easy question. What we can try to communicate the general public is that we see the vocalizations of the infants as a form of crying of the animals. So the way that we try to communicate that we are trying to identify one of the most innate behavior that we see not only in mice, but also in humans, which is a crying behavior. So this is the way that we try to communicate for general public our findings.

Dr. Kara Marshall 31:07
It’s kind of weird to study your nation. And I think as a neuroscientist when people say, Oh, you do neuroscience, what do you study? It’s, it’s something that kind of takes people back when you’re like, oh, urination. And it’s because I think societally, it’s not something people talk about, like when again, I was really stunned by the epidemiology. And you can pretty much bet if you’re talking to an older person, they’ve had some issue with their urinary tract. And so I think it’s actually, it’s been really neat to see that by studying these kind of basic functions, it opens the public up to talk about things that maybe they wouldn’t normally talk about, or even honestly, for adults to know that they’re not alone, that this is actually really common, and that they should seek out help for some of these issues, when you know, it’s sort of not not discussed very often. So I would say that, in some ways, urination is great and easy, because everyone does it and really connects to it because it’s a normal part of their lives, and lots of things go wrong. But on the broader scale, I think, for so long, especially in touch research, and like doing very basic science research about ion channels and stuff, it felt disconnected from the public. And I think that what’s been nice is kind of being able to really teach people the importance of just basic science. And I’m sure Dafni has strong feelings about this working in flies, because, I mean, I see the gorgeous, like, whole gut images, like there’s so much you can do in flies. And I think that, you know, conveying to the public that like figuring out these really fundamental questions, like answering fundamental questions is just about, like, how does this system work, even if it’s in, you know, a simpler model organism or something is really just like an important foundation. And I think that it is so critical to convey to the public, like basic science research is how we get to this translational stuff. And, you know, you don’t always know where that will come from. So you have to have a really broad foundation of basic science research in flies, and then, you know, mice.

Dr. Dafni Hadjieconomou 32:59
I do feel like that. And I think, just being in the business for a bit longer, you just sort of know, to filter down the information that you give to people, you know, people just ask yourself, what, what excites you and what are you working on? And you can start by saying, Hey, you know, I worked to understand how the brain works. And so you know, of course, everybody’s kind of interested in the brain. And then people are interested to find out that their neurons in your gut, which you know, and it’s a surprise to a lot of people still and I guess, then if you talk to them and bring it home, that if something doesn’t go really well, with that, you you might have an eating disorder, let’s say so I think you always have to link things, as Kara said, as, for instance, with the older people with something they have experienced and remove the jargon as much as possible. It’s not very easy. I think, if you just get better with the more you do it.

Dr. Yuuki Obata 33:55
Yeah, this is very difficult. But yeah, very important to communicate with the public. So in my experience, I have contributed to make a documentary film about gut physiology in collaboration with TV programs. So they they’re professionals. So we don’t we just provided the concept and the beautiful image of the gut. So that was, that did work very well, in terms of the delivering the message to many people.

Peter 34:24
Just speaking of like, things in the public. One of the things really just coming up to public perception now is the importance of science with the global pandemic that we’re having and coronavirus. What do you think the biggest hurdle or issue that our generation of scientists is up against?

Dr. Marcelo Zimmer 34:41
So I think we are not trained to communicate, so we don’t know how to communicate why we’re doing so that’s why I think we have this, this, this difficulty to talk to people. I mean, we don’t have any training to communicate what we’re doing to show the importance of why we’re doing. I would say for you Peter, it really depends well where you are as well, because I can I can say right now we have the opposite. People still don’t believe in science even more right now, because we have people that don’t think the vaccine is like this the cure for the COVID. So we have two problems in my vision, the first that we don’t know how to communicate. And there’s also political views about science, depending on the country, where you are.

Dr. Kara Marshall 35:20
Yeah, I agree. I mean, I’d say that I feel like in the US, politicians have been pretty good about like, continuing to fund the NIH, for example, even though there might be anti-science rhetoric in general, they kind of come through with some funding. But we need to be better not only about communicating the excitement of science, but just like how beneficial it is, like, I think these advances are so slow, you know, what’s coming on the market now might have been researched 10 years ago, or 15 years ago. And so it’s hard for a person and this is especially true in the private sector to look at this and say, Oh, you know, what you’re doing now is going to definitely economically benefit me and benefit humans. And so I think like, having a better narrative around these processes, and how they are slow, and it takes kind of people coming at questions from all different angles, which takes a lot of money. And I think that showing people that output and like the Human Genome Project was this moonshot. And it was it worked. And it actually like, has generated so much value, not only economically, but also just for knowledges sake, I don’t know, I think there’s like the two pronged argument could be made. So maybe scientists need to be better about communicating that.

Dr. Dafni Hadjieconomou 36:27
Yeah, absolutely. I think, you know, communication is a big thing. But I guess we’re also facing, perhaps an economic crisis I had, and that is going to impact science for sure. Across the board, so some countries will be more or less affected, I guess. So I guess this is where somehow we have to come together. And for more collaborations, perhaps and, and, you know, perhaps think of different ways of doing science, which is very hard, because careers are, you know, need to still be shaped. And it’s a it’s a hard one. But I guess you know, our generation could be perhaps more open. I don’t know, it’s a hard one. I think if I have to just find one that is going to be the most difficult hurdle to overcome. For our generation of scientists, I guess we are quite a lot at the moment, and very excited and the funds are might run thin for a wide base, I mean, or not, we’ll see.

Dr. Kara Marshall 37:27
I was just noticing someone asked about diversity and inclusion. And I was gonna say that one of the plans or hopes that I have in the future is, you know, of course, to have a really inclusive and diverse environment. But I think one of the ways to do this is really make sure that a broad range of undergrads get a chance to be in love. Because I think that’s the time at which most of us get our first experience with research. Like, I didn’t know anything about being a scientist, when I was an undergrad. I mean, I liked science. But I think that just making sure that a broad range of undergraduates that you know, may or may not have been exposed to science at all, like have the chance to go through lab. And what that can do is really allow us to practice mentorship at all the different levels, right, if you have grad students, mentoring undergrads and postdocs, mentoring graduate students, and like making sure that not only is everyone welcome in lab, but also people practice mentoring a diverse set of you know, others, right, and it’ll, you know, maybe people when they’re undergrads decide they don’t like it. But at the very least giving that opportunity and making sure that people from a broad range of backgrounds have the chance to access that is good. The other thing is outreach, I think is really fun. And we had talked about communication. But outreach to local schools is something I’ve always done wherever I am. And that’s also a really great way to introduce kids to the idea that scientists are real people. And it’s a manageable, fun career that you can actually pursue. And it’s not, I think it feels very kind of elitist if you’re not, you know, introduced to a scientist or whatever. So I think that encouraging communication, encouraging your lab members to seek out events where you go to schools and communicate science is a really good opportunity to both increase diversity and inclusion, but also to train people on communication and mentorship. So it’s like two birds with one stone.

Peter 39:07
Yeah, that’s really great. I think that question was from Yeka Aponte. I don’t know if you had a follow up.

Audience 39:12
Yes. I’m very delighted to be here today. I mean, thank you, Diego for inviting me. So I’m Yeka Aponte. I’m a tenure track investigator at the NIH. And Kara, your answer was a stellar because it’s about time that you know, especially when we think about gender, and we think about diversity & inclusion, that’s what he makes us stronger. And I think that we all have to when to reach, you know, the PI level to feel that we have a voice, you know, and that’s something that as you guys all said, no one teaches us how to be a manager we have to learn by doing. And I think that that’s kind of challenging. The other thing is that I recently became the director of the diversity and inclusion at the NIH, NIDA. And, and I think the one of the hardest and more challenging things is that, you know, expectations are really high when we join a lab. Interns, summer students, you know, and you have to understand when you have these kids that come from underrepresented backgrounds, they didn’t have the same privilege that most of us had, and the same training. So you have to put an effort to really, really get these kids to that level. And as Kara very nicely stated it, you have to start from like the undergrad level. I mean, if it were up to me, I would start, you know, for like, elementary school, but at least we have to start somewhere. And I think that this is the advice that I give all the investigators that you know, you have to be patient, you have to understand that perhaps in the first year, you’re going to want to get any data from that student, but the reward that you’re going to get one, that kid that perhaps is the first generation going to high school and college came out of your lab, you will feel so proud. I said, that’s my child, you know, that kid became a doctor because of me, because the training in my lab, so on a team that, you know, it’s about time that we educate ourselves about our conscious and unconscious biases, because we all have them, even if we don’t know. And, you know, this is something that, you know, I tell my lab members, we have to stop being bystanders, and you know, speak out & loud. I mean, I’m sure you’re all aware about this horrible paper that came out two weeks ago, and how female scientists not being good mentors, you know, I mean, on top of dealing with my background as diverse, I also have to deal with my agenda just to show people that yes, I can be a good mentor. It has nothing to do with my gender. So yeah, those are the comments that I just wanted to ask. But thank you, Kara, for just stating this at the level of you know, the trainees. So it was really enlightening for me to hear that.

Peter 41:37
Yeah, I don’t know if there’s any better way to close than that. I feel very empowered. I feel like we have to keep pushing the ball forward. We have to continue advancing science. And I really wanted to thank everyone here for coming to this Gastronauts Bite Size Summit. We really enjoyed your presence and we really valued your opinion. Thank you all so much for listening! Science is all about this open communication and how we can continue to advance it. If you can think of any other ways for how Gastronauts can improve, please feel free to reach out to us. If you feel like you’ve got something from this today, we’d love if you’d share this with a friend or a colleague and just get more people in the know-how about Gastronauts and about science. Thank you so much for joining us and thanks so much to our speakers.

Peter 42:48
Thank you all so much for listening and we’ll see you on our next episode. For more of our content, you can follow us on Twitter @gutbrains or visit our website at thinkgastronauts.com. The Gastronauts Podcast would be impossible without our incredible team. Meredith Schmehl is our producer and theme music composer, and special thanks to the founders of Gastronauts: Dr. Diego Bohórquez and the Bohórquez laboratory.

Episode 17: What Bugs Us

Peter 0:15
Hi, welcome back to the Gastronauts podcast. My name is Peter. And my name is Reem Hasnah, and we’ll be your hosts. Here at Gastronauts, we are committed to exploring communication throughout the body with a focus on the crosstalk between gut and brain. We invite speakers in this field to share both their research and their life journeys. So come join me as we explore the steps that go into shaping a scientist on the Gastronauts Podcast. Today, we have two great scientists Dr. Mary Estes and Dr. Dylan Dodd.

Reem 1:06
Dr. Mary Estes is a professor of biology and microbiology in the Department of Medicine at Baylor College of Medicine. She’s a member of the National Academy of Science, the past president of the American Society for biology, a fellow of the American Association of the advancement of science, and has authored over 400 articles. She’s a molecular biologist whose research is focused on understanding viral infections of the gastrointestinal tract. Her research group focus is to study how the viral proteins interact with receptors of the intestinal cells. Welcome, Dr. Mary.

Dr. Mary Estes 1:41
Thank you very much.

Peter 1:42
Dr. Dylan Dodd is an assistant professor at Stanford University. He received his training as a physician scientist at the University of Illinois in Urbana Champaign. his PhD work was done in Professor Isaac Khan’s laboratory, where he looked at the molecular mechanisms that were involved in how energy is captured by gut bacteria. And then he worked in Dr. Sonnenberg laboratory where he studied how gut bacteria contribute to small molecules that impact host physiology. He has leveraged his research to co found a company that engineers bacteria to modulate the immune system. And his research group’s focus is to uncover the chemistry underlying host microbe interactions in the gut.

Reem 2:24
Dr. Mary and Dr. Dylan. So what was the motivation behind you both going into research and studying these microorganisms like the microbiome and the viruses?

Dr. Mary Estes 2:36
So I originally had thought that I would go to medical school because I didn’t know that there were was another career that you could do research. And when I went to undergraduate college at a small girl school, we had a visiting prior graduate from the college come and give a talk. She was doing research in microbiology, and I had liked biology, I thought that I wanted to do immunology and I suddenly discovered that there was this whole other area of research. So I applied to graduate school. And then when I took my first class in microbiology, I learned about viruses. And I was hooked from then on. I worked on different viruses, tumor viruses initially, and then once I came to Baylor, I still worked on tumor viruses for a while, and then changed into gastrointestinal viruses after a few years.

Reem 3:27
So the carrier started with a spark.

Dr. Mary Estes 3:29
Yes.

Reem 3:32
Yeah. And you Dr. Dylan?

Dr. Dylan Dodd 3:34
Yeah. So I also was very excited about immunology, I actually joined MD PhD program straight out of undergraduate, because I knew I wanted to try to do science that could more broadly impact patient health. Unfortunately, you know, as graduate school goes, sometimes the lab you wanted to go to, there aren’t openings. And so I ended up going to microbiology, which I had never even studied as an undergrad. And I was captivated by it actually worked on trying to identify new enzymes for biofuels, if you could imagine, and the best place to look for enzymes that break down grass and lignocellulose is really the cows for stomach, the rumen. And so I did my PhD in rumen. microbiology. And it was very surprising for a lot of people that were my cohort and MD PhD. They said, Why are you studying the cow, but I immediately made connections between the metabolic activities within the cow’s stomach and what’s happening in our gastrointestinal tract. And so then I switched over to studying human colonic microbiota and their metabolic properties.

Peter 4:46
That’s super neat. It’s just so interesting how people get into their path into science and there’s just so many different paths to it. I guess for me, I had never thought I’d be studying the gut either. I never thought I’d be working on a podcast or the session with Reem. So I think it’s All about that spark.

Reem 5:02
It’s a small world Peter.

Peter 5:05
We’re really excited about the audience being really interested in asking questions. And we are going to start having people in the audience who have typed their questions ask their question,

Reem 5:15
Dr. McCann.

Dr. McCann 5:17
My question is for Dr. Dodd. I’m a research staff scientist in the Rawls lab. And we’re also really interested in microbial metabolism along the gut. And I was just curious actually what you thought about your sample set diversity. I know the Sonnenberg lab has access to tons of diversity as far as fecal samples go, but for your blood metabolites. I know, for instance, we have a hard time in really finding diverse populations and sample sets to look at for microbial metabolites. And I was curious about what you thought about that access? And how important it is?

Dr. Dylan Dodd 5:51
Yeah, thanks. That’s a great question. And I fully admit that our sample is not really capturing great diversity. It’s just capturing sort of the cultural background of the Bay Area, and especially tech companies. And in fact, we don’t have the metadata to say what the background is, or do we have any information on diet? So yeah, as you mentioned, you know, Justin Sonnenberg also at Stanford, in fact, my former mentor, has been studying the hodza, which is a sort of hunter gatherer population. And he’s got extensive metabolomics data that he’s working on in different populations across the world. And, you know, I think he definitely sees large changes in metabolomic profiles that vary across people. And so I think it’ll be really interesting as we start to build up datasets from culturally diverse as well as geographically diverse, as well as people taking diverse diets.

Dr. McCann 6:54
Thanks.

Peter 6:54
With regards to the diversity is that we experienced with our diverse diets and what not married, are you aware of how this diversity affects infections to viral gastroenteritis?

Dr. Mary Estes 7:06
I actually don’t know the answer to that question. Maybe there’s another a bile acid person that studies that this more broadly in different populations, or Victoria, do you have an answer?

Victoria 7:18
I think we’ve had this question, at least with individuals who have deficiencies in bile acid production. They’re more or less susceptible, but I don’t think we have an answer

Peter 7:28
Moving on, we have actually a question from Roy.

Roy 7:32
Hi, Dr. Dodd. I’m a student in Dr. Mary Estes lab, also joining us today. So I was wondering, my question is short, so I was wondering if the caffeine level you’ve just mentioned is now indulgence, right? So [I was wondering] you have some topic to say related to coffee or tea consumption and how affects maybe metabolite composition?

Dr. Dylan Dodd 7:58
Yeah, so I didn’t even mention it. I had caffeine on the far right of my plot of metabolites. And, you know, one, one point I like to make about that is actually 25% of individuals in our population had undetectable levels of caffeine. And that corresponds roughly to the caffeine consumption that we know, for, you know, typical individuals in the population. So 75% of people were positive, and then their concentrations ranged about as dramatically as the microbial metabolites. And so I just like to make that comparison to orient people and then also to say that, you know, that microbial metabolites are drug like molecules, essentially similar to caffeine. And their concentrations are varying as much in the population.

Roy 8:43
And may i ask one more question. So you just mentioned that there’s some potential limitations in metabolomics. So I’m wondering, are people developing a new technique to try to detect all undetectable metabolites so far, or that technique is improving?

Dr. Dylan Dodd 9:02
Yeah, that’s an important question. And, you know, if you look at, say, David Wishart’s group, who has the human metabolome database, you know, when they publish their papers, they go extensively into their samples with multiple different methodologies. And they may get very trace molecules that we would be unable to detect. So, you know, we’re, I do believe that we’re just kind of scraping the surface. But you know, mass spectrometers are sort of the workhorse of metabolomics. They have linear dynamic range on the order of four to five orders of magnitude. So I think it’s a really good approach right now, but I’m sure as we get interested in molecules that are at lower concentrations, we’ll have to change our methodology.

Roy 9:48
Okay, thank you.

Reem 9:49
So people are subjected to several medication and several foods and nutrients. And so how do you establish a stable set of microbial metabolites And how are they altered by pharmacological intervention? So what do you think?

Dr. Dylan Dodd 10:06
Yeah, that’s that’s a great question. It’s such a complex microbial community. And production of these molecules isn’t linear. It’s not one microbe acting on its own to produce these chemicals. It’s the microbial community interacting, exchanging electrons, transferring substrates. And so really, it’s, it’s incredibly challenging to tell how a dietary perturbation is actually going to influence a molecule like an amino acid metabolite. If you give fiber to people, you might actually see an increase in some of these protein metabolites. And it’s really difficult to understand. So I think to get at that, what we really need to start doing is human studies that are, you know, essentially longitudinal, studying each individual and how their metabolism changes over the course of a day over the course of different diets. And if we were able to do large scale studies of those sort of longitudinal analyses, I think we’ll learn an incredible amount about how diet influences microbial metabolites.

Reem 11:12
Yeah, that’s great. What do you believe is the most critical lack in our understanding of the host microbe interaction, to help us get into the precision of us having transplanted microbiome and then getting over specific diseases?

Dr. Dylan Dodd 11:30
Well, I mean, in the in the context of therapeutics, we don’t really know what dictates whether a microbial community will stay after transplantation. So it’s community dynamics, that really we don’t understand. We know that if you do a fecal microbiome transplant, you can actually track donor strains. And you can also track the original strains from the recipient. And you get some sort of mixture of that as assemblage over time. And so I just think that it’s going to be more of these very careful, multi omic types of analyses of FMT, that is going to allow us to understand more about the mechanisms and the dynamics of microbial interventions at the community scale.

Dr. Mary Estes 12:17
I think that what you said is absolutely true. I think the other big challenge at the moment is having technologies to be able to really address host micro biome interactions. I mean, one of the ways we’re doing that is with these cultures, we can put the cultures in anaerobic chambers, and we’re now making platforms or we can add the microbiota. And we do have a few examples. Now we’re putting microbiota in with a virus. microbiota can enhance viral replication, or in other cases where it can reduce viral replication. Now, that’s all in vitro, it’s reductionist, but that may be a way to that to begin to understand some of these more complex communities, perhaps in a simpler system. And then you would certainly have to go back ultimately and tested in animal models or perhaps people

Peter 13:08
Really neat. Andrea Marciniak.

Andrea 13:11
Yes. Hi, I’m a graduate student from the University of Virginia. And I had a quick question for Dr. Dodd, I’m actually studying how microbial metabolites are impacting the CNS. And have been thinking about this question a lot recently, of how likely is it that we will be able to modulate microbial communities long term to mediate their metabolism in chronic disorders? So I’m thinking things like, you know, depression or mood disorders? And is it likely that our work might be used in the future just for drug discovery? And that will actually be using these small molecules in a pill form?

Dr. Dylan Dodd 13:45
Yeah, I think if you look at sort of the biotech space, you know, they’re very much used to working on small molecules. But having biological entities like a microbe that’s anaerobic, and its entire suite of pathways, as well as its interactions with other strains, is really challenging to conceptualize and to bring through sort of the market. So I think the low hanging fruit are the small molecules that have specific receptors that you can actually dose. But a lot of the case in the microbiome is you want to actually deplete some molecules that potentially have a deleterious effect. And in that case, you might be able to block the receptor. But another strategy would be to make a fecal microbiome transplant, if you will, and potentially a synthetic FMT to actually replace the microbes in the community with ones that don’t produce that molecule or take the molecule the substrate down a different pathway. So there’s a lot of approaches people are taking, and I think all of the ones I’ve described, at least a few companies are working on. And so it’ll be super exciting to see what ends up working. And the the nice idea about the fecal microbiome transplant is you could potentially affect a long term change, if you could replace somebody’s microbiome with a synthetic community, but that has yet to be shown to be possible.

Andrea 15:31
Okay.

Maya 15:31
so my name is Maya Kaelberer. I’m here at Duke University. So we care a lot about good bacteria and bad viruses, if I’m going to generalize. What about good viruses? Are there symbiotic viruses that are symbiotic with like, maybe even the host, the human or even the bacteria? And how is their role different than bacteria? Or is it similar?

Dr. Mary Estes 15:53
I’ll give you two comments about good viruses. One are viruses that infect plants. So the tulips that you enjoy in the spring, and if you go to the Netherlands, there will actually be production facilities, in a greenhouse where a particular plant virus is added to make the white stripes on a red tulip or something. So that’s one example of a really good virus, I think.

Maya 16:18
Beautiful virus, yes.

Dr. Mary Estes 16:21
The other area where people are looking carefully now our bacteria are phage that actually come from infecting bacteria. But they may have some positive effects in the intestine. They’re not fully understood yet. But there’s some suggestion that the levels of phage may be important in outcomes of colitis. I think some of that is from animal models. I don’t know that we have good data in people yet. But I think that’s an area that’s going to be looked at, like carefully and there are beginning to be more and more stories where there are interactions between hosts genetics, bacteria and viruses that can either make disease worse, or trying to they I don’t know that I know of one that’s potentially better, but I think we’ll learn about those in the future.

Dr. Dylan Dodd 17:09
Are you interested in the bad bacteria?

Maya 17:14
I guess that’s true. My, my question was very one sided. But what about the bad bacteria?

Dr. Dylan Dodd 17:20
Yeah, I mean, we like to think a lot about beneficial microbes. And there are a lot of them, but not all microbes are commensals. And I mean, there’s opportunistic pathogens, which we know a lot about, especially esbl, for immunocompromised individuals, that can lead to enteric and systemic infections. But I think, you know, as we learn more about microbial metabolites, there are contexts where those molecules and their signaling pathways are beneficial. And there’s contexts where the same molecule on signaling pathway could actually be detrimental. And I think as we learn more about those specific interactions, we’ll learn about you know, what is sort of a beneficial context and one patient population versus another.

Dr. Mary Estes 18:04
I do know, so there are people in Houston that are studying Cryptosporidium, they also had done volunteer studies, and they had found that the levels of indle in the large intestine actually seemed to protect against crypto infection there are now doing experiments to try to understand exactly how that’s working. But that would be potentially an example where if you had the right bacteria making that you might be resistant to an infection.

Reem 18:33
We have a follow up question.

Elaine 18:35
hi. This is the Elaine Snell from England, London, about to go into lockdown. Question for Mary. So thank you and thank you both actually for your excellent presentations. I really enjoyed them. And Mary, I was immediately struck by the fact that you were talking about norovirus as a pandemic, the G 242 three strains that cause a pandemic that that norovirus kills 200,000 people globally every year. Well, you know, in the current circumstances, with Coronavirus, claiming all the attention whilst I’m not asking you a political question about how it’s been dealt with, I mean, you must have a view on you know, the the ways that norovirus is communicated and managed and lessons that can be learned for, you know, this other virus Coronavirus that also kills hundreds of thousands of people this year, I can imagine it must be quite frustrating for you to see the way it’s being managed in many respects, but I don’t want to put words in

Dr. Mary Estes 19:42
I mean, I think we know how to manage it. The question is whether the population will until we have a vaccine or prevented therapeutics. You know, you need to wear masks social distance. Wash your hands and actually those are the same Same rules for norovirus. So this is a virus that used to be known as the cruise ship virus. I think maybe that’s now taken over by our new pandemic Coronavirus. But it’s the same principles. When you get people in closed semi closed environments. You may have one person come on a cruise ship that’s sick. And if they don’t use good personal hygiene and go around touching surfaces, this is fecal oral spread. They’ll spread the virus very readily and you and you can have thousands of people on a cruise ship that will get sick with this. There have been ships that have been denied entry into ports in the last several years, because so many people are infected. So the principles are the same. I hope that if people will become educated about infectious agents, and how do you handle them, really probably could reduce the level of infection globally for many of these organisms. I mean, even the Coronavirus seems to be having an enteric phase and many people, it’s not clear that it’s actually spread through the feces but it certainly can infect the intestine. There’s been some suggestion that it may cause a pro inflammatory response in the intestine that may actually get into the circulation and affect other organs. That’s not fully proven, but as a hypothesis.

Elaine 21:23
Thank you.

Peter 21:24
Yeah, this is just having me think Reem and I were having a discussion earlier. I think every time before we have our meetings, we talk about how is COVID affected you? Are you doing okay in the time of Coronavirus? I was wondering, a lot of times these research in norovirusi and I guess research in the microbiome is not quite made it to the same degree of the public as Coronavirus has, and I was wondering how do you apply these findings from your research into your personal your day to day lives?

Dr. Mary Estes 21:49
I try to use good personal hygiene to prevent getting the infections and I think in terms of in the era that we’re in with Coronavirus. I think we’re trying to apply all the expertise that we have to maybe trying to answer a question about Coronavirus. So there’s been a lot of discussion about whether Abo blood type may be important or Coronavirus, infections. And there’s you’ll read one report that says that there is another that says it isn’t we have actually submitted a proposal to try to look at that, using our culture’s were so the histo blood group antigens are part of the Abo blood type system. And we have these cultures now that we’ve well characterized, we know what kinds of glycans are on them. And we’re proposing to try and use them to infect with Coronavirus to see if in the in vitro system, we can actually get a clear answer. And if we can to determine what part of the spike protein might be binding to the glycan where it might be binding and see if that might be able to be blocked in some way.

Dr. Dylan Dodd 22:55
Yeah, I can chime in on you know, how we use the microbiome and the metabolites that we’re studying in our day to day lives. You know, I have a six year old, and my wife and I, you know, are conscious about what we eat, and especially coming from Justin Sonnenberg lab, we have a copy of the good gut, on our shelves. And so we incorporate we try to incorporate more fiber into our diet. He’s a huge proponent of that. And there’s a lot of evidence that increasing your fiber intake is beneficial. We actually have a lot of fun picking that recipes randomly from the book. So I encourage you to take a look at it if you haven’t seen it already. It’s just a lot of fun. Justin and Erica Sonnenberg have done an amazing job with that.

Peter 23:36
I feel like the research that we do just definitely lends itself to, you know, impacting our personal life, especially if we study the gut, or viruses that infect our gut or viruses in general means basically like our understanding of our personal hygiene, how we live our daily lives-

Reem 23:52
and also the decisions we make on a daily basis. So whatever we learned in the lab, actually influenced our decisions in the future. I would like to thank our amazing audience who without them, we wouldn’t have this great discussion or these questions. Also a huge thank you from the Gastronauts family, to our guests, Dr. Mary Estes and Dr. Dylan Dodd, thank you for your precious time, and for taking part of today’s discussion.

Dr. Mary Estes 24:16
Thank you for inviting us. It was great to be here.

Dr. Dylan Dodd 24:19
Thank you so much.

Reem 24:33
Today we had a great episode, and a great discussion. And we knew that our body is far more complex than what we expect or know. Thank you all for listening. And we’ll see you on the next episode. We are really excited to announce that Gastronauts Global will take place this year and will start May 11! See you all in the virtual Gastronauts global. For more of our content, you can follow us on Twitter @gutbrainmatters or visit at our website thinkgastronauts.com. The Gastronauts Podcast would be impossible without our incredible team. Meredith Schmehl, our producer and theme music composer, and a special thanks to the founder of Gastronauts: Dr. Diego Bohórquez & the Bohórquez laboratory.

Episode 15: Shaping Our Appetite

Peter Weng 0:09
2020 has truly been a turbulent year and brought forth a new set of challenges on how we live and how we communicate. And as such, we have needed to find ways to adapt and grow. we’ve adapted our podcast to be a live stream through zoom. We’ve brought a new co host onboard. So everyone please give a warm welcome to Reem hasnah, a graduate student from Sidra medicine in Qatar,

reem hasnah 0:31
it’s a pleasure for me to be the new member of the Gastronauts family. Hi everyone.

Peter Weng 0:37
And we are so excited to continue diving deep on gut brain matters and learning about the scientists Behind the Science. So come join me as we explore the steps that go into shaping a scientist on the Gastronauts podcast.

Hi, everyone, we would like to welcome you all to our sixth year of Gastronauts. For those of you who have been with us from the beginning, we would like to thank you all for your commitment. For those of you just tuning in, we are happy to have you join our community. Here at Gastronauts. Our ambition is to foster discussion and spread knowledge on gut brain matters. What started as a seminar series led by Dr. Diego Bohorquez in 2015, has now expanded into an international symposium and a podcast aimed at exploring the scientist Behind the Science. Today, we invite you to join us in thinking and talking about why we eat. My name is Peter and I along with Reem Hasnah will be your hosts. So without further ado, let’s introduce our speakers. Dr. Lisa Beutler is an assistant professor of medicine at Northwestern University Feinberg School of Medicine. She is a physician scientist aiming to study how the gut and brain communicate with each other to maintain body weight. Dr. Beutler received her MD and PhD from the University of Washington where she studied how input from NMDA receptors onto medium spiny neurons, inhibitory neurons in the basal ganglia are critical for learning and Dr. Richard pomodoros laboratory. She then proceeded to specialize clinically in endocrinology, and began studying how a subset of neurons in the hypothalamus these AGRP neurons are involved in regulating hunger in Dr. Zachary Knight’s lab, and she is currently studying how obesity affects the ability of these neurons to detect certain nutrients.

Dr. Anthony Sclafani is a professor of psychology at Brooklyn College at the City University of New York. He has had a truly distinguished career of over 50 years and studying the neurochemical circuits that govern learn taste preferences. He has served as the past president of both the Society of the study of adjusted behavior and the obesity society, and has authored over 300 publications. Dr. Sclafani began his research into ingestive behavior in Dr. Pete Grossman’s laboratory where he developed a wire knife to dissect neural pathways involved in an obesity syndrome generated from damage to the hypothalamus. From there he has pioneered studies that have helped answer how specific features of food promote appetite, and the brain reward systems that are activated from the consumption of palatable foods.

Sometimes eating is not a reward. So what do you think of this?

Dr. Anthony Sclafani 3:35
So that’s a very good question. I mean, one way to look at it is that the brain is basically turned on by food almost all the time. And if the food is satiating, then it generates signals that temporarily turn us off. Or if we accumulate too much fat, we have long term signals like leptin, that keeps our appetite somewhat limited. But when you look at the behavior of these shame, feeding animals, for example, whereas a normal rat, when food deprived, would drink, maybe 10 ml of a sugar solution, if you lead to sugar fall out of its stomach, in the 30 minute period, you test it and might drink 50 or 60 ml of the solution. So there’s no inhibition and it seems to be just permanently driving this reward system. You know, there are situations like with anorexia nervosa or with animals that hibernate and they show cyclic changes in their approach to food, that the brain may be turned off to food but it might be a good biological bet that if there’s food there, and it’s a nutritious and it tastes, we’ll eat it when you can.

Dr. Lisa Beutler 4:49
Food is certainly always rewarding to me.

reem hasnah 4:52
Me too.

Dr. Lisa Beutler 4:54
I think I think I overall agree with that. But I will say that one of the reasons why I got it To this field, I think there’s a there’s a few reasons why I was interested in studying feeding and setting obesity. One is very related to my medical school experience in my life experience with obese people and wanting to figure out why they were obese, because it just makes their life so much harder for something that is really not within their control. But the other reason that I really got into this is because I personally come from a family where about half of us are complete food maniacs, and the other half of us really, you know, eat to survive, you know, dinner at dinner, they eat because it’s like Time to eat dinner. And so they eat a small meal, and then they can stop. And so I think that there’s like, people are probably tuned differently as to how rewarding food is and to how far they will go. And I think, you know, kind of related to that, if you look at an average healthy, like 25 year old guy will go eat a burrito the size of his head, and feel really great afterwards and kind of learned nothing from the experience that maybe that’s overnutrition and not great. But you take that same person at the age of 40, or 50, or whatever, at some later age. And probably at some point part of the way through the burrito, they’re going to be like, Whoa, if I eat more than this, I’m gonna feel not great later. So I think that probably breaks maybe get put on more in general later in life and are also on at different levels and different people.

Peter Weng 6:23
Do you think that sensing and ingesting behavior is altered with the aging process? So as we age, we tend to have new circuits new neuronal circuits or less of the effect of a specific sugar or a specific nutrients on our food preference?

Dr. Anthony Sclafani 6:41
That’s a good question. We certainly know with aging, the sensitivity of the olfactory system declines. And that could interfere with the appetite of elderly people. And unfortunately, many COVID patients have a lot of primarily odor, and that interferes with their attraction to food. We have not looked at aging animals for their post oral nutrient response. I think that’s an excellent question. And someone should write up an r1 application for that project.

Dr. Lisa Beutler 7:13
I totally agree. I think we don’t know from any of the models that we use, what aging does we just know, kind of from the human experience, and from mouse models, what Tony said about the olfaction going down? I think an interesting question is whether the homeostatic setpoint for body weight changes in aging people, does it get lower? Are we supposed to get skinnier? Does Britain think we should be skinnier when we’re older? Or do the negative consequences of eating too much just begin to alter our behavior? And hopefully in the coming years, we’ll find out the answer to that question.

Peter Weng 7:44
Has having a career in science of feeding altered your own food choices?

Dr. Anthony Sclafani 7:49
I’m not so sure I mean, I’ve been experimenting with some some recent developments in nutrition, there are these rare sugars called isomaltulose and allulose that have been promoted. Because I so multilocus is a sucrose type molecule that’s slowly digested. So it doesn’t produce a spike in blood glucose. And we’ve actually shown that mice will drink it. But they show let’s have a conditioning response to it. And allulose is a fructose molecule that’s not digested. It’s not metabolically use, you could buy cereal products that contain this fructose molecule that allows them to save the sugar, the cereal contains no sugar, because you can’t use it. And I’ve actually purchased the cereal. But it wasn’t particularly tasty to me. So I haven’t pursued that very much. But, you know, I’ve haven’t experimented with some products such as sweet taste inhibitors. But I’m not sure it really is changed my long term nutritional inputs.

Dr. Lisa Beutler 8:59
I think probably working in the field that I do, both in science and in medicine should have changed my eating behavior more than it has. But I think overall it has not. I think maybe if I’m being generous to myself, I would say that working in the feeding and in the obesity fields has at least made me try to focus on eating foods that I actually really love. And not eating foods simply because they’re available, but I still eat way too much.

reem hasnah 9:28
A question that I really want to ask you, Lisa. So as both we are females in science, how do you think your work might have been affected if you were in the field 50 years ago?

Dr. Lisa Beutler 9:40
Oh, man. I don’t know if I don’t know if I would have been in the field 50 years ago. To be honest, I don’t know how my life would have been different 50 years ago, but I’m very grateful to be doing science now. God I’ve not ever been asked quite this question. I will say that I count myself as someone who’s enormously privileged there are a large number of scientists and physicians in my family, my great grandmother on my dad’s dad’s side was a physician. And so I feel like I’ve experienced less barriers than many, many women. And many, many, certainly women of color have experienced and getting into science and medicine. So I want to start by just one expressing my gratitude and saying that I think that comparatively, I’ve had it fairly easy. But as I’ve transitioned to being a PA, and I have women trainees, I noticed the ways that they’re conditioned to behave differently than men still. And I’ve feel like I’ve worked to overcome some of that over the last 15 years. And my hope is that I can take my privilege and pay that forward to the next generation of women. Because I like if it had been 50 years ago, I may not have gone into science. And I hope that in another 50 years, it’s it’s easier still and more equitable still, for women and other groups.

Peter Weng 11:01
These times have been really changing. And hopefully, we’re going to make a lot more progress in the coming years for both, I guess the diversity and inclusion efforts and thinking about the changes that we have in our society has also made me think about the technological advances and how things are developing at a blistering pace, really, some of the work that you Dr. Sclafani started out as were these course dissections and creating lesions in the hypothalamus. And now we can actually target really specific neuronal populations, through light or through chemicals. How do you leverage the implementation of these latest technologies against methods that you have developed in your laboratory that, you know, are tried and true? And how do you go about including or incorporating collaborative efforts for things like this?

Dr. Anthony Sclafani 11:44
Right, I am in total, or of the work that’s being done today, in manipulating the brain with the super sophisticated procedures when I was in graduate school 55 years ago, which by the way, I don’t recall how many women we had in our class, I think it was very few. At the time, we were manipulating the brain by putting a wire in the brain and passing electricity and destroying 1000s and 1000s of cells. My PhD advisor, was one of the first scientists to actually put drugs into the brain to manipulate the activity of chemospecific ways. But at that time, believe it or not, we were putting the drug in the brain in crystal form, we didn’t have the technique to inject solutions. So we just stuck a crystal at the end of a stainless steel tube. That’s how crude it was. So in my lab, I never developed these super sophisticated techniques, we were manipulating the gut, and lucky to be able to get shamed, feeding animals and self infusing animals. And that gave us a lot to keep us busy. But I just loved the work that’s being done today by both men and many women.

Dr. Lisa Beutler 13:00
Can I add something to that? Even even as like looking on a shorter timescale, I had basically a five year interruption and doing science between when I finished my graduate work. And when I started my postdoctoral research, because I was finishing my clinical training. And even in those five years between 2011 and 2016, I got back into science and was like, holy crap, this is really, really different than how I left it. I was pivoting fields as well. So that was certainly a component. But really, the actual tools and technologies available had just completely exploded in the last five years. And it was both, inspiring and terrifying. So I think that this is an exponential process. And we’ll see we’ll see how it continues going. But also, from my perspective, as a pretty Junior investigator, I learn so much by going back to some of the old literature, not like, you know, when when somebody brings me a paper and says this is really old, and it’s from 2001, or something like that. But really going back to when people were thinking and only had the tools to study the very most fundamental aspects of biology, or much more fundamental aspects of biology. I think you can learn a lot and save a lot of reinventing some wheels, and generate a lot of really cool questions by looking at these older studies.

reem hasnah 14:39
If you could offer your graduate students, any self advice of wisdom of what you gained throughout your expertise and throughout your career, what would it be and why?

Dr. Anthony Sclafani 14:49
Well,I think you have to be willing to change fields as needed and utilize the most latest techniques but one early experience that I had that was very instrumental. When I first came up with the idea that there was a Nā Pali Coast tatse, I submitted an NIH grant, it was rejected. And I resubmitted the grant, and it was rejected a second time. And in those days, the good old days, you could submit it a third time. And I submitted the grant a third time. And I think I worm him out, because I asked for four years of funding, but they only gave me two. And then, in those two years, I had already collected so much private, you know, private data, I finally had a breakthrough and showed convincing evidence. And they subsequently supported the grant for 30 years, and no, they had a problem, you know, getting funded. But if I gave up too soon, I don’t know where I would have been. So if you think you have a good idea, don’t give it up too soon. Give it a try couple of times,

Dr. Lisa Beutler 15:58
as a trainee, rather than focusing on the duration of your training, or how close or far you are, from your next goal. Focus on whether you like going to work everyday or not. Because if you like going to work on more days than you don’t like going to work, I think you’re probably doing something right. And this is a it’s a long path for all of us. So don’t get too too hung up on the number of years, you are from your next thing, just enjoy what you’re doing. And use that as your barometer for whether you’re doing the right thing.

Peter Weng 16:31
That’s really great advice.

reem hasnah 16:33
Yeah,

Peter Weng 16:33
I think that’s something I’ve been doing with myself lately. Like, how many days do I wake up? And I’m happy doing what I’m doing,

Dr. Lisa Beutler 16:38
right

Peter Weng 16:39
And if the answer is less than 50%, and maybe need to change my career path or something,

reem hasnah 16:44
maybe not change your career, change your team, the team plays a huge effect. So when you have a great team of people, and then you want to wake up every morning just to have coffee with them, and just talk science,

Peter Weng 16:57
where do you see the field of gut brand communication going in the future? And how do you want to be a part of this?

Dr. Lisa Beutler 17:04
I think I see it as really turning into more than just one field. I don’t know that I consider gut brain communication to be a totally unified field. My focus is on body weight maintenance. Tony’s focus is on development of taste preference. Are those two things related? Yes, but Tony’s built, and I’m building an independent career on two aspects of this thing that are completely different. I think that the direction that I’m probably overall most excited about and hope to contribute to is understanding how genetics lead to differences that promote or protect from obesity, why body weight maintenance succeeds in some people and fails and others is what keeps me up at night. And I think that the way we’re going to ultimately understand that from a gut brain perspective, is to really drill down the molecular aspects of this genetic aspects of this,

Dr. Anthony Sclafani 18:04
we need much more translation in our research. Because while it’s very easy to condition, a mouse in rakk, with intragastric confusions, it’s much more difficult to demonstrate food learning and adults, adult humans, although children seem to learn much, much more readily, there’s something missing. And part of it is the complexity of the human environment and the foods that we eat. But there may be differences in how rapid humans form development, you know, developmental responses to gi changes. So some of our experiments have been have to be safely translated to human work and see how we can understand the difference between humans and rodents in this regard, because it’s easy to make animals obese and maybe prevent them becoming from obese obviously, in a clinical situation, it’s much more difficult.

Peter Weng 19:01
Yes,certainly, a lot of the goals with regards to obesity are not particularly for mice would be great if we never had any obese mice. But we want to translate this impact to humans in the socially complicated diseases like obesity and anorexia. What is the biggest barrier to communicating this information to the public?

Dr. Anthony Sclafani 19:19
Well, it’s very difficult. Every week, you’ll read the New York Times The Washington Post or some magazine, and they’ll highlight a recent study that came out and it sounds like you know, it’s the best thing since whitebread was invented. And it turns out they overhype the results. So the results were based on a small group size or some cases it’s based on limited number of human subjects in an experiment. So it’s very difficult for the news media, I think, to do a good job in presenting the data because they’re always looking for the hottest headline too, and then people they don’t pay attention to it. Because the story keeps changing. So now we have, you know, artificial sweeteners cause overweight, sugar causes overweight. But what should people do? They don’t know what to do.

Dr. Lisa Beutler 20:10
I think that overhyping is a huge, huge issue. And I think some people respond by not listening. But I think that unfortunately, some fraction of the population might respond by listening too much, and get really fixated on ideas that were sold to them as being potentially like a really great cure, but are either not practicable or not going to be effective, and it leads to kind of recurrent disappointment, and really doesn’t help anyone. And I think another another problem with communicating to the public is just that, you know, this is my job. And it’s really, really hard to stay on top of the amount of literature that’s coming out on this. And for somebody who doesn’t do this as their career, and even for the media to keep up on the literature as it really is, I think, is probably borderline impossible.

Peter Weng 21:03
Yeah, I think I’ve talked to some friends who are not really in the scientific fields. And a lot of times, they’ll be like, Oh, I thought we cured that disease already. And it’s just like, No, we’ve just learned more and more about it. But there’s still a lot of work to be done, to transition a bit about our communication to the public communication amongst scientists. And I really want to thank you both for participating in this new experimental seminar type format. And I’m curious to hear how you felt the dissemination of scientific knowledge has changed over the past 20 to 50 years, from an era before PowerPoint presentations, Dr. Sclafani to a time of now we have these virtual conferences, what principles have enabled the presentation to be so memorable or having a long lasting impact? And how do you think these types of presentations or dissemination of knowledge will continue to evolve?

Dr. Anthony Sclafani 21:53
Well, I think these new methods are very effective. We used to take as a weeks to prepare our slides for a slide talk. Now we could do everything almost instantaneously include the latest data, when I was a graduate student at the University of Chicago, we literally had to go to the library, and look in index medicus, or psych abstracts to find out what the research was today, on your telephone, you could look up PubMed and find out what the latest news is. But the latest news doesn’t always tie back to the oldest studies. So you know, you have to be very careful and looking at what’s the latest brightest thing and try and put everything in context. But as far as communication wise, I’m, I just love these new forms of communication.

Dr. Lisa Beutler 22:45
And I think that’s something that stayed consistent. I mean, I don’t I can’t speak from experience from 20 or 30 years ago. But something that has stayed the same, at least at the level of the literature, and as long as I’ve been on in science, is that whatever the technology is, that is used to disseminate new scientific stories, the key to doing so successfully is to tell a story. And the science that I read, and the science that sticks with me, and the presentations that stick with me, are those that really succeed in telling a story and answering the why, and then proceeding logically through the how and what it showed. And in fact, that’s how I came to be in neuroscience, which is a field that I when I was younger I swore I would never go into.

reem hasnah 23:29
For people who are considering to be a part of this field, what advice do you give them for young scientists, graduate students, or just high school students that might have listened to us?

Dr. Anthony Sclafani 23:42
My advice is, it’s to me. It’s been an exciting way of life. I spent 50 years or more in the laboratory. I was fortunate, however, to be funded, a little nervous if I was in a new student, what the funding situation is going to be. But it’s, it’s, you know, it’s exploration. Science is just wonderful to increase your understanding of the universe.

Dr. Lisa Beutler 24:10
As a young investigator, I am nervous about the funding situation and where my career is gonna be in five years. But as I alluded to, before, I like going to work every day like I look forward to going into the lab and seeing my students and talking to them and talking to my technician. And that’s I can’t think of a better barometer for choosing a career than that. And I guess my other advice, which I think is easier advice to give than probably to take, but something that I would advise young scientists or young people thinking they want to get into scientists is to not be afraid to reach out to us because as you can probably tell, we really love talking about what we do and answering questions and talking to young scientists and young people who want to do science is one of the highlights of what I get to do. So if you’re curious, send an email. If we don’t respond, send another email, we won’t get mad at you. And just keep at it and keep trying to get your your foot into the door. Like I said, that’s easier for me to say than to do. And that also comes from a fair amount of privilege. But hopefully, if this can get to some ears, that were reluctant to actually send an email because they don’t want to be a bother because they don’t know if it’s appropriate. It is, and do it.

Dr. Anthony Sclafani 25:28
I agree.

reem hasnah 25:29
Thank you, guys. A huge thank you from the gastronorm family to the audience who attended today’s episode, your presence matters the most to us. Also, we would like to thank our speakers, Dr. Buetler, and Dr.Sclafani, who gave us from their precious time to share with us their science and knowledge. A final remark. I’m really thankful and excited to be the newest member of the gastronorm family, and to be co hosting these episodes with Peter. See you in our next episode. Stay tuned. Thank you, everyone.

Dr. Anthony Sclafani 26:02
Thank you. It was a pleasure.

Peter Weng 26:03
Thank you all.

Dr. Lisa Beutler 26:04
Thank you very much.

reem hasnah 26:10
Dr. buechler. And Dr. Sclafani taught us many fascinating things. But the major highlights of this podcast is what we eat shapes how we eat, and that different nutrients activate different receptor and as a consequence, different pathways. Also, in this episode, we received a great advice that in science never stopped trying and keep on going, knock many doors and send too many emails. with that. I want to thank you all so much for listening, and we’ll see you on the next episode. For more of our contents, you can follow us on the new Twitter account gutbrainmatters, or visit our website thinkgastronauts.com the Gastronauts podcast would be impossible without our incredible team. Meredith is our producer and team music composer. And the special thanks to the founders of Gastronauts Dr. Diego Bohorquez, and the Bohorquez laboratory.

Jan 2021 – Piali Sengupta & Brian Gulbransen

The Gut That Moves Us

We kicked off the new year with a virtual discussion with Dr. Piali Sengupta & Dr. Brian Gulbransen on January 12, 2021.

Dr. Sengupta received her PhD from MIT, where she studied pheromone signaling in yeast Brent Cochran’s laboratory. She then did her post-doc at UCSF, where she identified genes that encode how olfactory receptors are encoded in C. elegans with Cori Bargmann. She was later recruited to Brandeis University in 1996. Dr. Sengupta is currently a professor of Biology at Brandeis University and was recently elected as an AAAS fellow in 2019 for her pioneering work on the molecular genetics of chemical communication and thermosensation in C. elegans.Her lab work has two primary research focuses: one is the cilia squad, which is focused on the mechanisms by which cilia form and function, and the other is the axis of taxis: which is aimed at uncovering how thermal and chemical stimuli are sensed by C. elegans

Dr. Gulbransen received his Ph.D. from the University of Colorado Health Science Center, where he studied chemoreceptor cells. He is currently an associate professor in the physiology department at Michigan State University. The focus of his lab is to understand how inflammation in the nervous system (neuroinflammation) leads to long-term changes in gastrointestinal function with a particular focus on the intercellular communication between glia, neurons and immune cells.

Nov 2020 – Dylan Dodd & Mary Estes

Learning To Co-Exist With Humans: A Microbe’s Story

On November 3, 2020, we held a virtual conversation with Dr. Dylan Dodd and Dr. Mary Estes.

Dr. Dylan Dodd is an Assistant Professor at Stanford University. He received training as a physician scientist at the University of Illinois in Urbana-Champaign. His PhD work in Professor Isaac Cann’s laboratory looked at the molecular mechanisms for energy capture by gut bacteria. He then worked in Dr. Sonnenberg’s laboratory, where he studied how gut bacteria contribute to small molecules that impact host physiology. He has leveraged his research to co-found a company that engineers bacteria to modulate the immune system and his research group’s focus is to uncover the chemistry underlying host-microbe interactions in the gut. 

Dr. Mary Estes is a Professor of Virology and Microbiology in the Department of Medicine at Baylor College of Medicine. She is a member of the National Academy of Sciences, the past president of the American Society for Virology, a fellow of the American Association for the Advancement of Science, and has authored over 400 articles, She is a molecular virologist whose research is focused on understanding viral (rotavirus and norovirus) infections of the gastrointestinal tract. Her research group’s focus is to study how the viral proteins interact with receptors of the intestinal cells.

Oct 2020 – Michael Krashes & Yulong Li

Tracking Behavior One Molecule At A Time

On October 6, 2020, we held our second virtual conversation with Dr. Michael Krashes and Dr. Yulong Li.

Dr. Krashes is a Section Chief at the NIDDK. He received his Ph.D. from the University of Massachusetts Medical School, his work focused on memory circuits and odor memory processing in Drosophila. His lab currently focuses on how the brain brings together information sensed from its external environment and its own internal states, including memory, to guide eating behavior (the study of neural circuits that guide the behavior of obtaining food).

Dr. Li is a Professor at the School of Life Sciences in Peking University. He received his Ph.D. at Duke University, where he utilized single molecule techniques to understand the role of specific proteins in neurotransmitter release. He then pursued a post-doc at Stanford University in the laboratory of Richard Tsien, where he developed a genetically-encoded pH probe to monitor activity-dependent release of neurotransmitters. His lab has expanded on his previous work and developed advanced imaging probes to untangle the exact chemical signals neurons are using to communicate. Dr. Li’s lab has used these probes to identify new receptors and neurotransmitters and characterize their role in specific neural circuits.