The Gut-Brain Connection with Emeran Mayer
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Did we just take one to the gut? We did. Oh, look at that. I see what you... A gut punch of a show. A gut punch of a show. How many more puns can we come up with? They will leave you with food for thought. Oh, another pun. I love it. Okay, you guys just got to tune in to figure out what we're talking about. The mind-body-gut connection coming up on StarTalk. StarTalk.

Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk.

Special edition. Which means I got Gary O'Reilly. Gary. Hey, Neil. How you doing, man? I'm good. Chuck. Good to have you, man. Good to be here. Of course. All right. Today, I'm checking out this subject. I love it. Okay. The gut-brain connection. Ah, some people's brains are the gut. Oh, we went philosophical straight away. So, Gary, tell us what's going on in this episode. Okay, so...

We've had everybody for our lives tell us they've had a gut feeling about something. Gut feeling. Yeah. And then we've seen people under stress dive. They don't say I have a brain feeling. No, this is exactly it. And we've seen people who are under stress dive into the fridge. We've seen people who are depressed not want to eat at all. And then we kind of work out that our guts are not standalone systems within our body. Right. That there is actually a direct gut-brain connection.

So that gut feeling may actually be a fact, not a fictional imagination of somebody. Now imagine, just imagine this, that every emotion you have has a mirror image within your gut. Oh, that makes sense. They call it hangry, don't they? Don't they, John? I'm hangry. I'm hangry. Spoiler, pun coming, that is obviously our food for thought, actually.

Ooh, I see what you did there. Now it's our time for an expo. And now I'm hungry. There you go. I see what you did there. Thank you. Okay, we have with us here in New York City, visiting us at the Hayden Planetarium right here in my office, a gentleman based at UCLA. We have Emmeryn Mabry.

Yes. I think I said your name correctly. Correct. You're a medical doctor at UCLA. You're a gastroenterologist, which is a lot of syllables to say you're a gut man, I think. We like that. Am I correct? Scrabble winner. You're also a neuroscientist. You hardly ever see those two in the same phrase because your brain and the gut. More increasingly you do now. Maybe so. All right. And you're also an author. Yes.

And the books, I got them here. Very simple. It's just Mind and Gut. Mind-Gut Connection. Mind-Gut Connection. That was in 2016 with HarperCollins. And then Mind-Gut Connection.

and you added a word immune connection immune connection so the mind gut is taking over the the body here yeah all right we'll see what that can take us and so my notes here say you're also a documentary filmmaker what what's up with that yeah i almost um didn't go into medical school because i was fortunate a retired businessman invited me several times to

Accompany him as a sound assistant to places in New Guinea and on the Orinoco River to the Yanomami Indians. And very formative experiences. Wow. The nice thing is I can now reconnect back. I mean, I was just a first-year medical student, had no idea about any of the things I know today. These people that we visited and lived with, the Yanomami people,

are very interesting group of people that have the healthiest microbiome on the planet. So, really? Found it out. And how do you... They poop three times a day. Well, that's where I was getting. I was like, how exactly did we determine that? That they have the healthiest microbiome. Are you digging into their poop in the forest? So, there was a scientist, Gloria Dominguez, married to a very famous gastroenterologist and researcher.

And they had the interest in studying the microbes of peoples around the world with what they called the vanishing microbes, you know, losing microbes. So they went to the Yanomami and did the most elaborate analyses. Didn't do it there, obviously took the samples. And it turned out that this microbial system that these people had is the most diverse and richest of anybody. They must have thought you were crazy.

Can I have some of your poop from my lab, Beck? I don't know. I know some places in New York where you get charged extra for that. So just to finish your resume here, so you're a professor in the Departments of Medicine, Physiology, and Psychiatry.

So that's an evidence of your breadth and what you brought together for your studies. And it's guided me. So my career has led me down this path, starting in the gut and then always having an interest in the brain and the nervous system. And at some point, they said it was necessary to connect to these other departments. And that's at the David Geffen School of Medicine at UCLA. Let's just get this started. Mm-hmm.

What is the brain-gut connection? And if I understand the timeline correctly, nobody was really talking about this until your books came out. Oh, really? Yeah.

So you wrote the book. You're a pioneer. On the gut-brain connection. It was a surprise to me because I've struggled in my professional career for literally decades to get this concept of brain-gut connections accepted as a major factor. Not just as an epiphenomenon, but as a major disease factor in medicine.

like inflammatory bowel disease and irritable bowel syndrome. Many of these what we call functional gastrointestinal. That's the IBS, I guess. You hear it all the time now. Yeah, on TV commercials. And so it was like,

It was kind of amazing that enthusiasm that gradually developed after the book, not the first year. It was not really popular the first year, but then gradually it picked up. And now if you go online, every second word is gut health and brain-gut connection. You hear about it all the time now in more of a cursory fashion. There's not a lot of in-depth talk about it. But what is your gut health?

Well, I mean, the gut, I would say, is, after the brain, the most complex organ we have in the body. Okay. It's not just a digest. It's a tube from the mouse to the anus. And for a long time, digestion and absorption and storage of waste has been sort of the main focus of interest. In the meantime, we know that 70% of our immune system is embedded in the gut. A big portion of our hormonal system, endocrine system, is embedded in the gut.

There's a separate nervous system in the gut. It's called the little brain. Mike Gershon here from New York, Columbia, sort of been a pioneer in describing and popularizing that concept. Wait, so some people literally have their brain in their ass? Yeah.

Yes. I know we probably don't know the same person, but we know they're like that. But to sort of ramp up the answer, all these systems in the gut are interconnected with each other. So the gut is like a brain. So who's talking to who? Is the brain talking to the gut or is the gut talking to the brain?

No, first within the gut, you have the immune system and the, you know, the micro cells that live in the gut and the nervous system in the gut, they all communicate with each other all the time. So you don't know it, you know, right now, if I could look inside of you with the right

lens, you know, I would see all these things interacting and talking to each other. Then you add the brain to it. And it's the same thing. There's a bi-directional communication going on 24/7, even when you sleep, always. Anything that happens at the brain level, as we said earlier, has a mirror image in the gut,

which we don't see. You see it on your face. So if you're angry, I can see it on your face. We can see that the gut contracting when you're angry. But also a lot of things that go on in the gut generate emotional feelings. Most of it, 95% doesn't become conscious. So that's the thing about the... So we have receptors and transmitters. I can say it, but what are they? How are they activated? How are they working? Obviously not emailing each other, but...

And just to clarify, when you said it's not conscious, it means, if I understand that, it means you will have a feeling and you won't know why, but you'll then act on that feeling. And if it's your mind-gut connection controlling it, it means you have behavior that's being commanded to you by microbes that you need a microscope to see. Yeah.

Yeah, but what I want to say is for a lot of people, they're not aware of this. You know, they're very oblivious to their body. They just have urges. Yeah, yeah. But like a sensation that everybody knows is satiation, hunger and satiation. Absolutely. So these are the most basic gut feelings that people have. And it's so funny you say that. When I was younger, my mother used to say I would eat and then I'd say, I'm still hungry. And she would say, just wait 10 minutes.

And your stomach will talk to your brain and let it know that you're not hungry anymore. Your brain will catch up with your stomach. And I don't know where she got that from, but damn if that's not the case. Yeah, a lot of people have lost that mechanism. A big part about obesity is that

that that signal that comes from the gut, this GLP-1, this molecule that everybody talks about, is produced in cells in the gut and goes to the hypothalamus in your brain and tells your brain to stop eating because you're full. A lot of people have lost that mechanism, that feedback.

why that is, but it's not clear. So what do you now do with mega doses of this hormone? Right. 100 times higher than what the gut produces. These are the GLP-1 injections that everybody sees on TV now, right? So that gives you that sensation. GLP-1, excuse me, but a pharmacist sitting here among us. We can't help it. It's on every TV channel. That's right.

And by the way, how do you think I lost 20 pounds? No, of course not. So you're saying, so this, I didn't know this. So this chemical that we see advertised 100 times a day is that molecule but heightened.

to create this sensation that really your body should have been producing all along? Yeah. It does a lot of other things. We don't know many of them because now all of a sudden, you know, it seems to be effective in substance use disorders. Right. People who take it find that

That they're urged to drink. So people who have an alcohol abuse problem, they stop abusing alcohol. They're like, yeah, I just didn't want to drink. And it's kind of ironic. When I first came to LA as a research student, I studied that hormone. And also it's sibling called GIP. There's another medication that has that.

And at the time, we didn't know. We were just excited to find all these substances in the gut. But nobody had a clue what they do. It took really literally 35 years or 40 years. Tackle whole body odor with Dove Men Plus Care Whole Body Dio Spray. Dove Men Whole Body Dio defends against all your odor zones from pits, privates to feet.

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How was this received when you emerged with this idea that your brain and your gut are connected in ways no one understood previously? Because as I understand medical school, you study the brain, you study the brain. You study the gut, you study the gut. And there's a siloing of the body where we are just bits and pieces assembled into one thing. Absolutely. And the idea that there's a connection will require that...

somebody in that mix has interest in more than one aspect of the human physiology. Yeah, and I would say, you know, I've had a long-standing interest in college on, in psychology and, you know, read all the stuff, Jungian stuff and the

So I came into medical school already with this background in brain science. With a perspective. Yeah, with a perspective. And I would actually say that the main reason I ended up in medical school, I thought I was going to go into psychiatry. But then spending a month in a psychiatry rotation convinced me this is not what I want to do. Those people are crazy. Never mind.

I might do it today. I might do it today because psychiatry has moved on a lot. It really has, yeah. But I had a very open-minded, a very charismatic mentor who really supported me in this from the beginning. So he was interested in isolating all these molecules like the GLP-1, not necessarily on the brain. And I said, can we combine this with the brain? And he was very open-minded, unusual, and very

But most of my colleagues either ignored it, didn't find that interesting, or then there were

Like in the IBS field, for example, there were like really entrenched interests of people that say IBS is a gut disorder. Forget about the brain, you know. Which is so counterintuitive from the fact that when we're all kids, we learn that the hip bone is connected to the thigh bone. All the bones are connected. Like you would think that it would be just, you know. The gut bone connected to the brain bone. That would make perfect sense, right? Totally.

We learn anatomy.

Day one. But it goes further than that. I think, you know, Western medicine, very successful, obviously, in many aspects. But it is based on a reductionistic view of the body, not an interconnected, not a systems biological. And it's gradually changing from the couple of developments. There's an entity now called functional medicine, non-scientific entity. But also in science, there's more and more scientists that say,

think in systems. Interconnectivity between the systems. So it will take another 10 years, I think, and then it will change. I mean, they'll catch up with you. How about that? So we spoke about GLP-1, but you've got cortisol and serotonin, the stress. I suppose we love eating. We have an experience when we eat certain foods that maybe you'll tell me yes or no with serotonin being released in the gut or dopamine. And then

The cortisol, like I say, you're diving into the fridge because you're under stress and you're going for the sugars or the fats or whatever it is. I mean, how long did it take us to work all of that out? And we've got this image of the person who just broke up with their loved one. Gallon of ice cream. Gallon of ice cream. Halligandass. Watching a sad movie crying. What's up with that? That's what sad movies do. The gut likes Halligandass ice cream. Or any other ice cream. So...

So there's some very smart people that have worked in this area. So surprisingly, it was never really identified as the brain-gut connection. You know, they always talk about appetite and stress and substance use disorders. But it never really became sort of an essential part of it. But that's really how it started. We knew these things for quite some time. Very good scientific studies support it.

But it's not really become a specialty, you know, because of this dominant paradigm, I think. Right, yeah. So going back to Chuck's insight into anatomy, the knee bone is connected to several other things in the body. The gut bone connected to the brain bone. So how is the gut connected, A, to the autonomic system? And then the vagus nerve, spelled with an A, not an E. And what does the vagus nerve do? Because we've heard about it. I couldn't tell you actually where it is in the body. It's right here.

Yeah. The vagus nerve? Okay. Above your clavicle, where your neck is, and it runs down. Why are you telling me this and not the good doctor? All right, doc, tell us, where's the vagus nerve? Where you said. Exactly. Yeah, so the vagus nerve...

First of all, it's a bidirectional pathway. It's like a bidirectional freeway. Most of the traffic goes from the gut to the brain, to the brainstem, and then to higher emotional centers. And 10% goes the other way. So, for example, to simulate the acid production in your stomach, that's a vagal phenomenon. That's why people used to cut the vagus nerve for ulcer disease. This was a dominant. Wow.

Wow. Which is amazing when you think about this is only like 30 years ago that we have absolutely no understanding. It's like cutting off your foot because you have an ingrown toenail. Exactly. That's insane. That's comparable. So where on your body is the vagus nerve? It goes down from your brain stem. Okay. Down your neck. That sounds like just what Chuck and I said. Did Chuck say that 90 seconds ago? Yeah.

Just shows you not. Okay. But what's important is to realize, so the vagus nerve has branches to all your organs. It monitors every organ function 24-7.

The ones to the gut have received a lot of attention because we were always wondering why is 90% of the traffic going from the gut to the brain? There's not that much happening that the brain needs to know. So now we know there's all these receptors on the vagus nerve for serotonin, for GLP-1, for GIP. So disproportionate.

what we call afferent or sensory signal to the brain is related to this complexity that goes on in the gut and the signals it gets from the microbes. - It's a processing hub. - Yeah. So I'm still confused. How does any of that relate to your immune system? So the immune system, as I told you, more than 70% is located in the gut sandwich between the layers. - Seven zeros. - Seven zeros.

sandwiched between the layers of the gut and in very close communication to the microbes in the gut, microns away. So how nature could engineer something like that as a potentially deadly influence of microbes. So a micron is a millionth of an inch. I mean a millionth of a meter, I guess. Yeah, of a meter. Right, so that would be...

a thousandth of a millimeter would be a micron. Yeah, so the immune system is very close to the vagus. Some of the sensory nerves go into this immune system in the gut and they pick up signals that the immune system produces like cytokines, for example, that's studied. And that has all kinds of effects on your behavior, you know, like cytokines.

Fatigue, chronic pain, some of it. Inflammation. Oh, yeah. I got to come at... So, a pause. Then...

What is the urge that people have to, what do you do when they clean out the colon? - A cleanse. - A cleanse. There's this urge to get it all out. - Oh, I can answer that for the doctor. - And/or people prepping for a colonoscopy, they're cleaning everything out. So all these microbes that it set up shop to communicate with the brain, they just flow out your body just for the benefit of one of your colleagues to look up your butt.

All right. And so are we destroying this hard-earned microbiome every time we get ready? Chuck had an answer. What's your answer, Dr. Chuck? Okay, so here's my answer. For the cleanse—

That's bullshit. So that's the first human shit, but yeah, no no I'm saying the actual cleanse itself. I mean, I know it's supposed to get rid of yours. That was a joke Oh, I'm sorry. Isn't that a good joke? Oh, I thought you were saying it like okay. Never mind. You said it's bullshit. No, you said no It's human shit. Yeah, see we missed the no

Because I would have laughed at that, because that's funny. Excuse me. I'm sorry. I missed it. But the colonoscopy, that's so that they can look at your intestinal lining. Yeah. And the good stuff that you need is in the walls of your intestinal lining. So cleaning that out so they can look at it, you're not getting rid of. Okay. Yeah, so two answers from myself. The first one, I would contradict what you said. Oh, you think it's real. So, well...

You know, Ayurvedic medicine for thousands of years has propagated these colonic cleanses. So what is the benefit? Because everything that I read says that the benefits are negligible at the best.

Okay. Unless... Wait, that would be health benefits, but suppose you just feel better. Doesn't that count? I mean, you know... Doesn't that... Are we talking about how you feel? I feel better when I punch a puppy. Does that make it... What? I'm sorry. Did I say that out loud? Okay. Yes. Anyway, tell me why it's good before I get arrested. So for a long time, this has been dominated or driven or motivated by this concept of cleansing. So you...

Humans are obsessed with cleansing. They spend a lot of money on cleansing. So not just cleansing the colon, but a cleansing diet. In not 19th century Europe, but in modern times, yes. Cleansing. But it's become very popular again. You're talking about your ancestors. I know. I need to dig. You take a bath once a year and only if necessary. Yeah, but it's our birthday. You've got to celebrate. So with microbiome science...

There's a certain potential explanation why people have been doing this over thousands of years. Why? Well, because it reestablishes a balance within your colonic microbiome. Okay. It has not been studied scientifically, but it's certainly... You're saying it's feasible, though?

So even though we don't have empirical scientific peer-reviewed studies, it's a feasible concept that this could be the case. It is conceivable. So the blueprint for your microbiome doesn't disappear with that. So you cleanse out the population. The blueprint is there and the body can reconstruct the... Okay, so it's a jumpstart. A jumpstart. All right, fine. You have changed my mind on this. It's like stripping off a layer of...

paint and then just it re-evolves itself to bring a new layer of paint that's nice and shiny. So if our microbes are not important in our gut,

over evolution, we'd have got rid of them. It's like sleep. We are never more vulnerable than when we're asleep, right? Yet we've not evolved to do without sleep. Why haven't we evolved to do without microbes in our gut? What? How? How come this? Because they're the OGs. They're the original life forms on this planet.

They've been here for 4 billion years. You know, it's 3.5 billion. You can't get more OG than that. Exactly. 3.5 billion before. Original gut. Nicely done. Thank you.

But it's been the most successful evolutionary development because every organism today from the cockroach to the butterfly to humans has a microbiome, a gut microbiome. Wow. There's not a complex living organism. There's a number I calculated and it just freaks people out that if you go to your large intestine and take one centimeter slice through it,

Just one centimeter. One centimeter. That's four-tenths of an inch for those who, for mer- For Americans. Americans. Mer- That's right. Don't bring any of that metric crap over here. Talking about mer- boy. Talk to me in inches. You ain't talking about millimeters, centimeters. That four-tenths of an inch lives and works more microbes than the total number of humans who have ever been born.

So that we think that we're in charge, but we're just a darkened, anaerobic vessel of fecal matter for microbes. We're an Uber ride. That's what we are. We're an Uber ride for microscopic organisms. For microbes.

Yeah, I read something recently in a book by one of my favorite scientific authors, Antonio Damasio, on this comparison, the early life forms, you know, which had a lot of intelligence. I mean, these microbes on the planet must have a phenomenal amount of intelligence collected over three and a half billion years. But they couldn't do long division, so... Yeah, yeah, yeah.

But I mean, they don't have a mind and obviously they can live in homeostasis with each other and with the world. Their main benefit is that they now can connect to our brains and

can influence a conscious entity. So they do have a mind. So if we've got the original gut microbes, the OGs, as we now like to refer to them, three and a half billion years, they've invented their own language. They've had to have their own alphabet of sorts. So how are they communicating with us from their little hidey hole in the gut? You know, they have millions of genes compared to our, you know,

number of ten thousands. In these genes is stored all this information, how to build these molecules, how to use them, so their language is basically stored in their genome. So, their own history of three and… Yeah, yeah. And… Yeah, I know, I was about to swear before I got to the B. Billions and billions, okay.

So then when they settled, the first microbes settled in these floating tubes of the first marine animals, they interacted with these floating tubes and there's something called lateral gene transfer, that they transfer some of these genes that they had about their language into these animals. And fast forward,

That was the first version of the so-called little brain of the gut, or the enteric nervous system. And then with animals developing heads, becoming polar organisms, some of that same information about language was transferred to the brain. What is a polar organism? Having a head and the opposite end, whatever that is. Okay, okay.

Yeah, so our language, our ability to think comes, uses the same building blocks as the microbes developed over billions of years. I mean, that to me is one of the more fascinating ideas. Incredibly fascinating. So seeing as how we have the gut-brain connection, seeing as how microbes have their way of communicating with us, is this...

the superhighway that is used for psychedelics? Because we're ingesting and yet everything's going off up here in the brain, but not so much down in the gut. So, is this the sort of exploration here? There's a lot of things going on in the gut that we don't know yet. Like serotonin plays a big role as you know with the psychedelic experiences activating a particular serotonin receptor, the 5-H2A receptor,

which is in the brain. So these psychedelic experiences, many of them seem to be related to that receptor in the brain. Now, the same receptor is also in the gut and on microbes. And we don't know what effect this actually has. And it can't be an accident, right?

Right? It's a co-evolutionary thing. Right, okay. So is the mind desperate to try and expand? And that's why it's so active to find something like these psychedelics and then just whiz them up to the brain? Yeah.

Yeah, I mean, humans have probably used psychedelics for a long time. Long, long time. And based on their experiences, initially by accident that they ingested a mushroom, all of a sudden, the world... Is that the sort of, when you talk about an evolution, just by accident eating a mushroom, is that sort of the beginning of a stoned ape theory of evolution? That's a phrase? Stoned ape? Yeah. What is the stoned ape? I mean, I've been to the zoo, but I've never seen an ape get high. Well, it's a...

I would just love to sit there and watch a chimpanzee tripping its balls off. I would love that, but I haven't had the pleasure of seeing it. Out in the wild, I'm guessing they'll stumble across a mushroom, be curious, and eat it and go, whoa. So isn't the basis of where Gary's coming from, why do we have receptors for psychedelics at all? Unless it was the purview of the microbiome that delighted in it.

Yeah, that's a really interesting question. I can't really answer it. I can only say partially based on personal experience. I guess I can say this even though it's not recommending for people to do it. I am. I'm recommending for you to do it. The good doctor here can't. I'm letting you know, everybody should do psychedelics. I mean, I can't do it for legal, medical, legal reasons. Sue me, please, but do it.

But the experience that you have, and everybody says it's a universal human experience. It's not that one person gets this realization of the interconnectedness of yourself with the environment, the planet. You get a totally different...

Oh, yes, without a doubt. So you, Chuck, you... Oh, God, yes. You missed a few shows a while back. Because you... I traveled to Costa Rica to do ayahuasca for an entire week. Wow. And I will tell you that it changed my entire life. It changed my perspective on everything. Did you get funnier? Not at all. Yeah.

And you know what? While I was in one of my transmeditative states, Mother Aya came to me and said, I can't help you with the funny son. I'm so sorry. Okay. So just to be clear, when you did this, it was a fully supervised process?

Oh, got you. Activity. You know, they are licensed. They're fully supervised. And they have medical staff on hand. It wasn't somebody who sold you something on the street. No, nobody on the street. And you did it in the back alley. And by the way, now that I do not recommend. I say please find a professional and have somebody there to supervise. Make sure that there's medical staff on hand. Do not go to somebody's house.

Okay, and do not go to some dude with a ponytail who's just like, dude, I've been a shaman for like so long now, and I would love to turn you on to the universe. But if he doesn't have a ponytail, it's okay. And it's not a party drug. No, it's not. If you're looking to get high, don't do it because it's not that kind of high. Okay.

Yeah, so one of my speculations is, again, partially based on self-experience. So there's different phases to the psychedelic experience. There's the initial rush that you get with a lot of visual and auditory experiences. But then it has this long-lasting effect. I mean, at least 24 hours that you notice it, if you pay attention to it, with your ability to communicate and to talk, that you've never talked like this before before.

about yourself and your emotions and then even past it, one experience, a lot of people say that one experience, just like you said, can have a life-changing effect because from now on, you're going to look at the world differently. So that's...

Easy to understand knowing that it interferes with brain neurosynapses. How does that connect back to the gut? Well, the slow effect, you know, I mean, the thing that what happens in your brain initially is a fast response. It's being absorbed in the small intestine. Oh, because you ingest it. Yeah, you ingest it. And it's got to get through your, so it only gets to your brain as the microbiome allows it.

Right, true. But it's the part that is not absorbed in your small intestine, which happens immediately after ingestion. It's the part that goes down into your colon. And then these longer-lasting effects, I would not be surprised if they're mediated by microbial, you know, they add things to it. When they stimulate it with the 5-HDA2A receptor, they produce other molecules that then create this long-term experience.

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All right, given that there's this connection, there's so many other psychological features of human behavior. Some good, some bad, some failures of our psychological profile. Neurological diseases, this sort of thing. How much of that can we blame on our microbiome? Our current knowledge is pretty much based on what we call...

association studies or correlations. You take a big population of people that have a particular diagnosis and then you look at their gut microbiome and it's different. You have to even know to do that as part of the study, right? But it doesn't prove causality. That's the thing. So I personally think of, I'll give you a few examples. I think anxiety, anxiety

In my opinion, I've studied this pretty intensely for the first part of my career. We know so many mechanisms in the brain and the effect of early life adversity that predispose you to have great anxiety. So we know so much about the brain mechanisms that some people try to propose, you know, it's the microbes that cause anxiety. Has any of your research gone into diet relation to Alzheimer's development?

Yes, we're part of a big US-European consortium on Alzheimer's disease funded by the NIH.

There's definitely pretty strong evidence that... It's the NIH National Institutes of Health. The National Institutes of Health. Thank God we have it. Thank God we have it now. What time is it? What time is it? Let me tell you something. Now you sound like Flay the Flay. And I would say there's pretty solid evidence that, again, what we call dysbiosis or altered composition of the gut microbiome

plays a role. And there may be heterogeneity, you know, it's not, Alzheimer's is not one disease, it may be different pathways. Diet and what we now have, you know, it's become sort of the magic word, systemic immune activation or systemic inflammation is clearly one of the main risk factors for not just Alzheimer's, but also all the other ones, like Parkinson's. But Alzheimer's is also, it's interesting. So,

Anything preventive for any of these chronic diseases, you want to go to what's referred to as an anti-inflammatory diet. That's an emergent awareness of our health. Is that butyrate? Anti-inflammatory, the phenol? - Yeah, and butyrate is... - Polyphenols and those sort of things. - A largely plant-based diet. - Mediterranean type. Once you have Alzheimer's, severe symptoms,

There's evidence that a ketogenic diet, which is not a good diet for the average person because it starves your microbes. But in that case, it's beneficial. And there's one disease entity, refractory seizures in young children where a ketogenic diet is also... Oh, my God. Ketogenic is...

is basically protein all the time. Fat and protein. Fat and protein. Right. Keeping your body in ketosis, a state of ketosis. Right, right. Which means you don't have access to sugars or any carbohydrates. So your body basically uses the fat. So that is... And of course, presumably before we were agrarian, our ancestors, they ate dead animals, right? Or berries, of course, if they could find them. But they were... The caveman diet is this, correct? Well, but...

But going back to my personal experience on the— As a caveman? You have to say that. I was just hanging there. I didn't do it. Living with the Yanomami on the Upper Orinoco River. So they're surrounded by animals, by birds, by fish, by big mammals. They only eat a very small amount of animal products.

they mainly eat tubers and berries and plant-based stuff. That's why they have the healthy microbiome. That's why they have the healthy microbiome. And that has been studied all the way, a colleague of mine at UCLA, Elaine Chao, all the way into the production of GABA, this inhibitory neurotransmitter in the brain on a ketogenic diet. That's sort of like Valium. It sort of tones down the nervous system. How much of this is

us really knowing a lot of it or how much of this is us just beginning to understand? I know you've been doing this research for decades, but just how much more of this do we not know yet? What can we look forward to? I think we're just scratching on the surface. No, really? Yeah. I think, well, I was just thinking about these millions of genes that the microbes have. We only know... Why don't they have more genes than we do? That ain't right.

Yeah. Been around a little bit longer. Or is it the collection of genes represented in the diversity of microbes that you're referring to as millions of genes? Yeah. Okay. So if someone prepping for a colonoscopy, they just got rid of the entire population of microbes. So why, other than the value of the exam to prevent colon cancer,

How do you get back your microbiome if it's all in the toilet? It comes back fairly quickly. You know, I would say... Where's the recipe? So the blueprints to reassemble it is in your gut lining. I'm asking the medical doctor here. Well, I'm telling you. Did I ask the two of you? No, but you got it anyway.

- Yes, so you need to know. - Okay, so you're saying we are chemically equipped to reproduce the microbiome that is suitable for us. - So there's a form of colitis or a very serious form after antibiotics where you basically just destroy your microbiome. - Oh, because the antibiotics, while it's getting rid of whatever was your condition, it's biotics. - It's killing everything. - Killing everything. - So it's called C. difficile colitis. That's the name.

So one therapy that is very effective is a fecal microbial transplant. It's the only disease where that works. A poop transplant. It's a poop transplant. So whose poop are you taking? Oh, you had to ask? I'll tell you this. Not dog poop.

So, there's now people have identified donors that are free of any disease, any family history of disease, and that have a diverse healthy microbiome. So, these are the donors. So, one of the most effective therapies is to get one of these transplants, these poop transplants.

And so for a while then, the person who got this transplant has the microbial composition of the donor. Yes. Because he or she himself didn't have it. But if you look at this like a few weeks later, a few months later, the person's own microbiome is being reassembled.

And the reason is possibly because the microbes are not just floating inside the lumen, the inside of the gut, but they also inhabit the mucosal lining. And that's probably where that information is stored, of the blueprints. That's exactly what Chuck said. I did say that earlier, but that's okay. I don't need to be right. I just need to be funny. But if you're right and funny, that's even better. I guess so. So...

What about advertisements for gut ailments? And every time I see one, I say, do I have that or could that happen to me? And one of them shows up a lot is IBS or irritable bowel syndrome. Do we know the cause of that and can gut health fix that?

Yeah, so this is something that myself and my group have studied for, I would say, four decades. You're failing badly because people still have it. Get back to work. What are you doing here? Well, fortunately, finally, after 30 years of writing articles and review articles on it,

It's basically called a disorder of altered gut-brain interactions. They did bring the brain in. How about that? Finally. And the most effective therapies are brain-targeted therapies, meaning...

Simple relaxation techniques, mindfulness-based stress reduction, gut-directed hypnosis, cognitive behavioral therapy. They're better, more effective than any of these medications. Now he's getting all new agey on this. So how is this received by, quote, Western medicine to have these...

A lot of resistance. And also the pharmaceutical industry. Of course, you need a pill. They need a pill. They need a pill, yeah. You can't meditate a pill. I mean, we're getting inundated with supplements. We're getting inundated with probiotics. Yeah, probiotics too. There's all these, you know, eat this yogurt because it's got the bacillus, the active microbes. Do we really need that?

So, the official organization of gastroenterology has published, you know, they always publish these statements, these expert statements,

And they said there's not good enough scientific evidence to actually recommend probiotics in general as a treatment for IBS. However, there are patients who benefit and there's also, there's different types of probiotics. If you now go on the internet, you know, yeah. Yeah, it's a whole industry. Yeah, it's a whole industry. And like,

Like when I wrote my book, somebody came to me who was a retired Hewlett Packard engineer who said, do you want to be my partner? I want to start a probiotic company. So we just go to these big warehouses and get our organisms and then we package them and then market them. So that's a lot of people have. You said no, and he's a billionaire now. Is that what you're saying? I have not seen him since then. All right. So there's a lot on the table.

right now and and we're inundated by ads that are telling us one thing or another about medicines that are being put forth what would you say is a best practice going forward not that you're prescribing for an audience that is surely diverse but what kind of things should we be aware of as we put food in our pie hole

- I love that word. - Just a glimpse on your diet. - Yeah, that's a-- - Don't judge me 'cause I like pie. - So first of all, I would say it's not just the food. You know, it's the lifestyle. The food is a big part of lifestyle. Same with the Mediterranean diet.

I no longer call it the Mediterranean diet, but the Mediterranean lifestyle. If you go to Italy in summer, you will experience that, the social interactions, which is a big part of it. You know, like all the studies. Does it not go back further than just lifestyle? Community eating, being around people. Does it not go back further than that to the soil? Where our plants come from and the...

animals eat that then it comes down the food chain to us. Yeah so like the awareness of why your gut health may not be optimal is key to start out with because then you realize it's not just it's not just what you eat but where it's grown and how it's grown and how do you eat it in which context and you know. That's easy to say but suppose I don't care about any of that and I do

poop regularly. What should I be worried about? And I don't have mood swings. I don't have IBS. So does that make me rare on this spectrum of gut-bion issues?

It seems right now, you know, all of a sudden since this has become acceptable as a topic for dinner parties, which was not the case even 10 years ago, it seems like everybody now has, you know, like 40 or 60% of the population has some kind of a poor gut health. You know, I'm not sure if that's true or not, but...

What is it about them that manifests this fact? Do they live longer? Do they never have diarrhea or constipation? What is the metric?

for you to arrive at that conclusion? You know, for these people... Because we should just do what they do, if that's what you're saying. Well, if you lived with them, you would realize we can't go back. There's no way back. There's no cable. There's no streaming. I'm not eating leaves and grubs and... Grubs? Yeah. Tasty grubs? Some are tasty. But what we know about them is, you know, so they have an interesting thing. They have a lot of little wars, and the wars are invading another village,

to get women from other villages and they do this to prevent inbreeding. So this is part of their culture that they always... They could just have a dance, you know? Just, hey everybody. A social. Yeah, just come on over here, we're going to have a little dance, you all meet one another, you know. Anyway, so... Sorry. So a lot of them die early because they're bitten by a snake or eaten by a crocodile or...

A lot of good the healthy gut biome did for them. But if they don't have... But that crocodile has the healthiest gut of all the crocodiles. Yes. And that's why crocodiles smile. But here comes the interesting part. If they don't die early from one of these accidents, they live into their 80s without any medication. With no medication. No medication. Wow.

And no medical system. And no medical system. That is impressive. And no medical insurance or anything. Well, we don't have that here either. So let's be honest. This is America. We do not have health care. It's an illusion, people. Don't get mad at me. Vote differently. Okay? All right. So you've spoken of a mixture of traditional Western medicine and lifestyle, diet, even sort of Eastern philosophies and ways of living.

Is there a way to sift the fact from the fiction for someone who's just exposed to all these ads and other YouTube videos? Someone who's seeking guidance and not being inundated with all of this misinformation. Thank you.

Very difficult for the average person. Very difficult. Especially in today's media climate. And it's going to get worse, you know, for political reasons. Listen, don't blame me. I'm very healthy. I have a doctor who said that I have the best health that anybody could ever be. You know it and I know it. So healthy. That's what I am.

Yeah, one of my missions at this stage of my career is really to provide that answer for people and the trust and the transparency. I think there always has to be, there always has to be evidence supported. And the evidence could come from scientific studies, high quality, not, you know, five mice, and then claim that this is...

But it also can come from traditional success. I have this developed this criteria. Somebody is stuck around for 5,000 or 6,000 years. There's got to be something to it. You cannot just dismiss it. Turmeric is a good example. That's so true. Anti-inflammatory. There's now scientific studies. Ginseng is another. So there's several things that I think you can...

But then there's obviously in the middle of all of this is an enormous number of stuff that's placebo. And placebo is not a bad thing. If people feel better and they want to spend the money. People poo-poo. I shouldn't use that phrase. People denigrate placebos. But if it works, we should study placebos.

Yeah, and so there's a lot of high-quality research on the brain's mechanism to create the placebo response. But is that another gut-brain connection, the placebo, if your brain perceives that it's working? Yeah. So the placebo is an evidence-based mechanism

that the body does itself. It's the enemy of the pharmaceutical industry, obviously. That's why it's bad-moused. It's a wonderful thing. If you're a really good doctor and healer, you utilize the placebo response extensively. Interesting. Isn't that...

That's pretty wild, man. Yeah. So, Doctor, what brings you to New York City? It wasn't just to do this show with us. So, I have an invitation to this Integrative Health Symposium that's going on tomorrow and into Saturday.

And I have a couple of one panel on IBS and one talk about increased stress responsiveness of people. Okay. Especially stress is a buzzword. A killer. Of late. Yeah. We're all stressed. Well, cortisol and stress, very linked. Well, welcome to the town.

Yeah. And thanks for making some time in your schedule. And speaking of gut biome, don't eat any dirty dogs, okay? Hot dogs? Yeah, man. Oh, no. You need that. Yeah, you know. You got to live here. See, the people who eat it every day. Oh, they're immune. You can't be not from here and do it. Right. It'll kill you. It'll kill you. Yeah, we built up a resistance. It'll kill you within the hour. Right. But you go to the one with the dirtiest fingernails. That's what you do. That's it. That's the best one. That's the guy. Don't look at me like that.

Thanks, Neil and team. It was a pleasure to be here. Pleasure was ours, sir. Thank you. You guys are an amazing team. I've done a lot of podcasts, but not like this. There's not too many out like this. Dr. Ameren Mayer with a 2016 book, Mind and Gut Connection, followed six years later by Mind and Gut Immune Connection. Nice. All right. It's all there and more.

Gary, thanks for being here. Pleasure. All right, Chuck. My stomach hurts. Well, go talk to your gut and see what happens. My gut is feeling just fine. Good to know. Thank you. So this has been StarTalk Special Edition. Neil deGrasse Tyson here, as always, bidding you to keep looking up.

Springs here. Flowers are blooming. Birds are singing. And allergies? Yeah, they're back too. Sneezing. Watery eyes. When they hit, you need a tissue fast. That's where Kleenex Ultra Soft Tissues comes in. Whether you're at home or on the go, Kleenex Ultra Soft Tissues have you covered. Allergist-approved Kleenex Ultra Soft Tissues are gentle on your eyes and nose, so you can power through allergy season without missing a beat.

Because while allergies are unpredictable, staying prepared is easy. For whatever happens next, grab Kleenex. Your old or broken phone can let you down. But at Verizon, trade in any old phone from our top brands and get iPhone 16 Pro with Apple Intelligence with a new line on MyPlan and iPad and Apple Watch Series 10. After all, you don't want your old phone to die on you when you're lost. Perfect. Or for your broken phone to glitch at the worst possible time. Hey, can I get your number? Oh.

Trade in your old phone for a brand new iPhone 16 Pro, iPad, and Apple Watch. Visit Verizon.com today. Additional terms apply. Service plan required for Apple Watch and iPad.