The Gut MD: “95% of Serotonin is Made in the Gut!” The Food You Eat is Tied to Anxiety & Depression

It turns out that 95% of serotonin is produced in your gut, not your brain. Come on! I was in a dark place, and making that change completely radically transformed my health. Because I had that moment – I'm a medical doctor and I care a lot – I felt like I had no choice; I had to bring this into the clinic.

A board-certified, award-winning gastroenterologist, two-time New York Times bestselling author, the man with the master plan for the microbiome: welcome Dr. Will Bulsiewicz!

Dr. Will Bulsiewicz: We've got 38 trillion microbes. Now, this is by the way more than we have human cells. Really? Yeah, we are less than 50% human.

How many times should we be pooping a day? Let's just get right to it. I'm just curious, like I'm so glad that you asked this question. Inflammation influences anxiety and depression. Oh, 100%! You could do all the right things physically, but if you don't heal emotionally or psychologically, you can't take off as a human being. 100%! That is fascinating. I think this is the missing piece that a lot of people haven't heard, and they need to hear. Wow.

Welcome back, everyone, to the School of Greatness! Very excited about our guest; we have the inspiring Dr. Will Bulsiewicz in the house, who is the US Medical Director at Zoe, um, and also a New York Times bestselling author and also a gastroenterologist. Amazing! Welcome to the show. Very excited.

Thank you, my friends. It's great to be here. I'm very excited. There are so many things I want to talk to you about, the first one being the connection between the gut and the brain, and how much gut health actually impacts mental health. There's a lot of anxiety, stress, overwhelm, mental diseases, or um, just blurriness mentally, it feels like, in society today. How much does our gut health impact our mental health?

Yeah, well, we've seen these conditions escalating: depression, anxiety, different mental health disorders, different cognitive disorders, including Alzheimer's disease, Parkinson's, things like this. And the question is, what the heck is going on here? And when you see things changing this quickly, it's not genetic. So you have to take a step back and say, what is it about our environment? What is it about the way that we live that ultimately is resulting in this effect? Because we didn't have all these mental health issues 50 years ago.

Well, they existed, but they didn't exist to the level of intensity or the number of people that are being affected by these things as what we see today. Right. Right. And these are complex issues, so to sit here and pretend it's just this one thing – you know, hey, it's the gut microbes, that's all that matters – that would be oversimplifying it. But I think that the important point though that the listeners need to hear is that they do play a role; these gut microbes do play a role.

So, in order to introduce this conversation, I feel like let's take a quick moment, take a zoom out, and let's talk about the microbiome, which is the living microorganisms that are a part of our body. There are 38 trillion microorganisms that exist, covering all external surfaces of our body. So they're on our skin, on our, on the top of our head, our scalp, literally; they're crossing my eyeball as I sit here and look at you and talk to you. Um, but they're so small I can't see them, so thankfully they're not affecting my vision in any way. So these are like little bugs, little bugs. How many? 30 trillion? 38 trillion bugs. 38 trillion. We call them gut bugs, but really we're talking about bacteria, bacteria that is around, that's on, that's on the outside of our body and our inside of our body.

Well, so here's an interesting thing about that: it turns out that what's inside of our body – we're talking about our intestine – yes, is actually outside of our body. Yeah, bizarre. I know. Our intestines are on the outside of our body. Okay, so here's the thing: your tube is a, your intestines are a continuous tube. It starts at your mouth. Now, you're a tall guy, much like me, okay, but the average person in the United States, somewhere between 20 and 28 feet, okay, is this continuous tube of intestines. 28 feet. Okay. The tube is never broken. All right, there is no point where things that enter into the tube leave the tube and go into the body unless they're absorbed by the body. Interesting. So basically what that means is, because it's a continuous tube, it starts at your mouth, which is outside of your body; things are outside of your body. You swallow them down; you may think of them as being inside your body, but actually they're within this tube and they never actually enter into your body. So all the way through, this is actually an external facing surface. Interesting. You're interacting with the outside world, which is one of the key points to understand: is that you're, you're interacting with the outside world within your intestines. So this is the reason why, by the way, Leis, that 60 to 70% of our immune system lives in the wall of your intestine. This is the home of your intestines. Like people may think of the bone marrow as being, hey, that's, that's where immune cells live. No, no, they're born there; they may be born in the bone marrow, but then they move to other places, much like you were born in Ohio and I was born in New York and now you're here and I'm in Charleston. Um, the immune cells move, and most of them take up residence within the mining of the intestines. And the reason why they're there is because this is actually where we're interacting with the outside world, and so we need our defense systems in place in that location. All right. So anyway, so here we are: we got 38 trillion microbes. Now, this is by the way more than we have human cells. So we are, yeah, we are less than 50% human.

Wait, how many human cells do we have? Uh, about 30 trillion. 30 trillion human cells. 38 trillion what? Non-human cells. Non-human cells. Really? Yeah. So they're clearly outnumbering us. There is no doubt; you are definitely less than 50% human. And actually, if we took your 30 trillion cells, um, if we took your 30 trillion cells and we removed the red blood cells and the platelets, which by the way aren't like the classic cells, like when we think of cells, I think we all have a picture in our mind of like the cell with the organelle, the mitochondria, all these things, right? So if you took just those cells, you are actually about um, 90% microbial and only 10% human. And so a microbe is not a human element. No, it's not. And it's also not a part of our body. Um, they take up resonance after birth. That's crazy. Yeah. So the water breaks, the water breaks, um, mom goes into labor, and for the first time the baby is exposed to the outside world, and with that come a flush of these microbes. And actually, passing through the birth canal is a gift from nature, because as a child passes through the birth canal for the first time, it's being exposed to this world, this microbial world that dominates. And they've been around, Leis, um, so like humans, we've been around for about three, three and a half million years. Um, ARA, which live inside of our microbiome, okay, they're not bacteria, they're not fungi, they're these weird things, but they produce gas. Right? So when you pass gas, think of ARA. Um, they, there's a, an archaeological site in Greenland where they found four billion-year-old ARA. Four billion years. And we think that that's the oldest life on this planet. Wow. So these, these microbes, uh, they have been around forever. They've survived everything that exists. No matter what happens in this world, no matter what happens, there will be microbes; they will continue to exist. Um, and they're an important part of us as humans, which is really the key point, because um, we can't be our best selves without our microbes there to support us. Come on! Really? So wait, so how much of our bodies is actually human versus non-human? What's the percentage? Uh, so human versus non-human, clearly less than 50% human. Okay, clearly less than 50%. Some would argue 10% human. And then if we were to talk about your genetic code, you are less than 1% human. Come on! Yeah. So what are we? We're a mishmash. We're superorganisms. We're superorganisms, wow, that are a mishmash of these microbes. And we think of ourselves in isolation, like, hey, we're these, we're these big strong humans, um, but actually the big strong humans would be quickly broken down into weak humans if they didn't have these microbes to back them up. They back us up. If we didn't have these alien organisms crawling over our body, we would not exist, is what you're saying. Well, I mean, we think of them as alien, but they're more native than we are; they've been around for four billion years. Interesting. So yeah. And so now with the gut-brain connection, so the gut, uh, we rely on these microbes; this is where they live. They are most concentrated within our colon; that's their number one location. Yes, they're on our skin and our mouth and a woman's vagina, all these places, but they're most concentrated in the colon, and and they're involved in these core essential parts of human physiology: digestion of our food, access to nutrients, shaping our immune system, which is inflammation, our metabolism on multiple different levels. These microbes are key players in our metabolism, um, our hormones. So like for men, androgenic hormones that make us feel masculine, they play a role in that. Yes, there is, there are connections between microbes and erectile dysfunction. Wow. Yeah, really. Absolutely. Go. Okay, this is how we get guys to listen to the show. Okay, how do I have better erections? All right, now what do I do? Um, but for women too. For women too, it's connected to um, estrogen and estrogen metabolism and multiple different conditions, including uh, endometriosis, polycystic ovary syndrome, etc. Wow. So um, and then the last part is our brain, um, which is what you started this question with, and our gut-brain connection, our gut-brain connection. And we can unpack this to describe the multiple ways that those microbes are communicating to our brain, but the bottom line is that your brain clearly has a best friend, and its best friend is your gut, and they're, they're talking to each other like teenage girls all day long. They're just on the phone nonstop or texting um, all day long. And the brain is taking signals from your gut and adapting to them, but it goes both ways, because the brain is sending signals back to the gut, which can affect the way that we digest our food. Wow. So can you have a healthy brain if you have an unhealthy gut? Uh, I think that to have the healthiest brain possible, it is essential to have a healthy gut. Really? Yeah. I think that we need to be quite intentional about the way that we go about these things, because we can kind of just stumble into our health, um, or we can wake up and see that here we are, and we have 38 trillion microbes; they're constantly evolving and changing. The food that you eat today will change your microbiome by tomorrow, and with those choices you are shaping the microbiome, and that microbiome will affect health throughout your entire body, including your brain, including your ability to function, including your ability to maintain memories, including your ability to focus and get stuff done, and your long-term cognitive health, which includes things like uh, Alzheimer's and things of this variety. Wow. So if someone is feeling like they have symptoms of some type of mental health challenge, they're feeling maybe they have ADHD, or they have depression, or depressed thoughts, or they have anxiety, or stress, or overwhelm, what are three things they could do to start recognizing how to fix them? Well, I'll give you three things, and they all connect back to the microbiome. Um, I would start with food. The food is the, the food is our most powerful lever that we can pull in terms of shaping and changing the microbiome, and there are simple choices that anyone can make. Um, and this doesn't have to fall under a dietary pattern or a label; it's just changing the way you eat. What would be for that first one? What would be the top five foods that everyone should eat daily to optimize their gut microbiome? Okay, I can give you a top five, but can I start with this essential rule? Yes. Which is diversity of plants. M. All right. So eating as much variety of different plants in our diet. We have to be intentional about this if this is what we want, because the problem is the food system is not going to do that for us. You go into the supermarket; they've distilled it down to 75% of the calories in our supermarket is three foods. What are those three foods? Wheat, corn, and soy. Wow. Yes, that is 75% of the calories in the supermarket. Now, granted, most of those are ultra-processed, right? So I'm here to advocate for real food: fruits, vegetables, whole grains, seeds, nuts, and legumes. That's at least five. We could add mushrooms. All right, those are broad categories, and we can get more specific if we want to, but to me it's about getting that variety. And this is not just an idea or a concept; this is actually scientifically proven. So in a, in a study called the American Gut Project, which by the way was international, but it was run out of UC San Diego, um, they, what they found is that at the end of the day, when they did their analysis, above everything else, there was this one rule: the diversity of plants in your diet was the number one factor in predicting who had the healthiest gut. And the number is 30. 30 different plants. Wow. Per week. 30. 30 different plants. Wow. Per week. Now, all fruits, vegetables, whole grains, seeds, nuts, and legumes include those 30; they count. Okay, all of them. Right. So you want to have 30 different ingredients every week of plants, at least. Wow. At least. But you know what? I don't even tell if I've tried 30 different plants in my life, Leis. It's like you and I need to spend more time together. Exactly right. It's like 30. Wow, that's incred- You start, take a smoothie. It could be Monday morning. Okay, take a smoothie: bananas, uh, blueberries, um, greens of your choice, whatever ones you like, chia seeds, hemp seeds, chia seeds, hemp seeds, flax seeds, um, we're already up to six. Okay. Right. You want to add in some raspberries or some other kinds of berries; we could easily get this up to 10. Got, got you. You're making pasta sauce; why would you just do pasta sauce? Why not throw some plants in there? Oh, there you go. Right. Onions, garlic, uh, basil, oregano, um, those count too. Spices count. Why is the, you know, if someone's like, listen, I just like my five to 10 plants a week, I, I eat healthy plants, I eat mostly plants, I non-processed foods, is that good enough? Or is it really more about the you adding more and more of the diversity as possible as opposed to just broccoli and spinach by itself? The average person in the United States, 10% of their calories comes from actual plants. The number one plant is the potato. Uh, right. We're not talking about optimal nutrition here. There's a reason why people in the United States are suffering through the health-related issues that they currently have. We need to make changes. If we simply added more fiber to our diet, we would radically transform the health of this country. Really? Yes. And that person who's not necessarily eating a lot of variety but is eating a lot of plants, number one, I give them a standing ovation; their diet's great, starting point; they're way better off than the average American is right now. Right. We all, though, should be looking to optimize; we all have opportunities to do better. So if you take that diet and you add more variety to it, they will reap the rewards of that. And the reason why is because every single one of these plants has unique properties that are, are number one going to affect our microbiome, right? So these microbes, they're kind of like us in, in many ways, Lewis, um, they have personalities; they have some of them are, are not nice, um, they have clicks; they have certain ones that they tend to hang out with, and they work together. Um, they also have taste buds; they have different food preferences. Not every microbe, believe it or not, likes kale, right? But you can train it to like kale, or you can get rid of the ones that don't like kale. I guess you can train it to like kale, but there's going to be a lot of microbes that are going to be hungry if the only thing that you ate was kale. Interesting. Right. So every single plant is feeding certain families of microbes. Interesting. So the more diverse and expansive that you have with your plant diversity, the less hungry you'll be as well, is what I'm hearing. 100%. So if I just eat broccoli and spinach and kale a few times a week versus, I might never feel like I'm, uh, full, and know it's like, I still want more, right? So I need some different carbs or some snacks or things to feel more full, but if I'm hearing you say, right, if you have more diversity of plants more frequently, you're going to feel more satiated; you're going to get the fiber that your body needs to be less hungry as well. Yeah. So, so satiation, like feeling full, um, is an important concept these days, right? We have all seen the rollout of Ozempic and these other GLP-1 type agonists. What is this GLP-1 that we're talking about here? This is a hormone; it's a gut hormone already produced by your body, right? And makes you feel full. Now, I'm not sitting here and going to try to pretend that like what you eat is going to have the same effect on your body that a drug does; that's not what I'm trying to do here, but I want people to understand that here we exist where 95% of Americans, 95%, are deficient in fiber. This is our most prevalent nutritional deficiency, and fiber is what actually leads to the release of GLP-1, and GLP-1 is what, exactly? GLP-1 is glucagon-like peptide 1, which is a gut hormone, which is what Ozempic is. Ozempic is GLP-1. Okay. And it has these different effects in our body, including helping us to control our blood sugar and making us feel full. Interesting. Which is the reason why Ozempic is used for diabetes and for weight loss. When someone takes an external drug like Ozempic to create a chemical, I guess, formulation inside of the body, the brain, the gut, the nervous system, things like that, to either turn on or turn off certain things, how effective is that versus, you know, having 30 plants a week and just eating the foods that will make you feel, that will turn on these hormones that you're talking about that the drug would do and make you feel more satiated in a full way by itself? So, um, first of all, we have to fully acknowledge that these drugs are highly effective; like there is no doubt that they work. They're getting results. They're getting results. But what are the long-term effects of these? We have no clue, right? We have no clue. We don't have the data yet to say what the long-term results of these are. What we do know with complete clarity is that if you stop using the drug – by the way, they're very expensive; they're very exp-, thousands of dollars per month – wow – right? And are we ready to commit to doing this for the rest of our lives? Because when you come off of the drug, you go right back to where you were before. Yes, you rebound immediately. So, um, flip side though, I think, I think it's important at the same time as we're having this conversation about Ozempic and these types of weight loss drugs, again, like I'm not here to vilify them, okay? But when we're doing that instead of changing the way that we eat, the behaviors, right, the problem that exists with this is like, yes, we can measure weight loss, and when people lose weight, there are different things that can certainly improve, and they become more healthy, but is the only thing that matters for human health our weight? That is not the case. There is so much more to um, us as humans and our determinants of our health beyond just whether or not we're obese, skinny, or what our body habitus is. And so we need to look at that bigger picture. The bigger picture is that when we optimize our diet, we have opportunities to improve ourselves metabolically, which includes improving our weight, which includes improving our blood sugar control, but we also have opportunities to prevent other diseases far beyond what Ozempic is capable of preventing. What also sounds like, you know, as I'm hearing you talk about this, it sounds like if someone's taking something like Ozempic to lose weight, if that's their main goal – like, I want to lose weight; I want to take this drug; it's going to help me be less hungry – but if someone's losing weight but they're just still eating processed foods and they're not having plants and they're just eating less junk but they're still eating junk, how would that affect the brain and the gut connection to feeling good beyond just losing the weight? Um, so the, the, the data are clear that when we consume an ultra-processed diet – which in the United States today, 60% of calories are ultra-processed foods – so more than half. These are foods, by the way, that did not exist 100 years ago. Crazy, right? So like what we're describing was not possible for our great-grandparents; there's no way they could evade the diet that we currently eat because these foods did not exist. And our kids, 70% of calories in our kids come from ultra-processed foods. Wow. And there's no doubt that they cause a shift in the microbiome; it's a shift towards what we call dysbiosis. So it's the opposite of what we see when we eat a diverse diet. Diverse diet leads to a diverse microbiome, and that is a healthy microbiome. When we shift towards ultra-processed foods, we're actually contracting the microbiome; we're empowering the ones that love sugar; we're empowering the ones that um, create inflammation, and they're signaling the direction they want to go in; they want you to go in. Hey, you want, you want more of this sugary drink? You want more candy? You want more chips? They're telling your brain you need this. There are, there are interesting studies to suggest that our taste buds and our cravings are driven by our microbiome. Wow. Yes, it's almost like we don't have control sometimes, or maybe it's felt in the past like, I want this so bad. Yes, I can stop myself, but my desires and cravings are just like, I'm going to go to the store and buy candy right now. And is that the microbiome kind of signaling and constantly telling us, get this, go buy this, you need this? I think that they play a role in that, full. Yes, I think that they play a role in that whole impulse. Um, and yes, that certainly exists, but also the beautiful, exciting thing is our taste buds can change. Mhm. Right. Those impulses can change, and you can get yourself to a place where what you crave is actually something that's good for your body and nourishes your body. How long would you say it takes to change your taste buds from not craving sugar and processed foods into craving a diverse, plant-based, healthy options? I think it really, you really start to see the benefits in four weeks. Four weeks of doing it consistently. Of doing it consistently. But by the way, don't, I don't recommend that people try to flip a switch. Um, now there are some people that works for, but like to me, we want, what, what I want is sustainable, right? Something that you can actually stick with, not extremes. Not extreme. We don't want yo-yo; we don't want to be swinging all over the place, right? So we want consistency, sustainability, and we want it to taste good. Yes. So start with the stuff that you enjoy; introduce simple, sustainable choices and build from there, right? And as we start to build, we start to build momentum, and our microbiome is given a chance to, to change with us. Wow. So I say four weeks is what it takes to really make this huge change, but really, I would rather that you do it over the course of six, six months, a year, right? Because then, by consistently doing this, you are actually going to completely reshape your microb- body. So getting back to the question about, you know, ultra-processed foods and um, and brain health, um, what you're going to create with these ultra-processed foods, an inflammatory microbiome, and inflammation is an essential feature that exists in many different cognitive disorders and mood disorders, including depression, including anxiety. So from my perspective, inflammation influences anxiety and depression. Oh, 100%! How much would you say – sorry to cut you off there – but how many, what's the percentage of the human population would you say has an inflamed gut and brain? Oh, gosh, um, it's hard to put an exact number on that, but I think what we see, if we were to zoom out even in America, then maybe, yeah, in America, if we just focus on what's happening here in the states, if, if you zoom out for a moment, think of all of the digestive disorders that exist: so obesity, digestive disorders, metabolic issues, immune issues, meaning autoimmune type issues that are like hugely on the rise, um, hormonal issues, right? And you go down the line and you think of these things, and I haven't even got to the brain yet, heart issues, and basically what I'm saying is the gut microbiome is a player in all of these different wow conditions. Wow. So if the gut microbiome is, is a player in these conditions, and you have these conditions present, you've already proven, you've already proven what the state of the microbiome is, and then the question is, how is it affecting your brain? Right? And could you, could you have better energy, better focus, better ability to, to do um, tedious, hard things during the day? And the answer would be yes. And the way that that starts is by changing, changing your diet. Wow. Yeah. So the number one thing you said is food. We covered some of these foods and 30 different plants. And 30 different plants. Yeah. What are the next two things? We talked about the top three things. So on food, real quick before we move on, there's a study called uh, the SMILES trial, okay? Where they took a plant-predominant – not it was not vegan; it was a plant-predominant Mediterranean diet – uh-huh – so it has some fish and shellfish, things like that. 100%. And it was um, as effective as medication for the treatment of major depression. Really? Yeah. Just putting them on that nutritional food plan. Yes. For some reason, I don't like the word diet because I feel like it's a restriction, yeah, as opposed to an addition of health, right? It's not about like eating less and starving yourself. I think that's what people associate the word diet to; it's like starvation, cutting out all foods that I enjoy and being miserable. That's what people think when they think of diet, and so I'd like to try, I try to keep correcting myself to being like, what's the healthy food plan? What's the nutritional abundance plan that we're going to step into? Abundance is the right word for what we're talking about here. 30 different plants or more; I'm asking you to add more variety, not take away, not restrict. So it's the opposite of what we've been told by traditional fad diets. Yes. So all right, number two. Yes. So we want to improve our mood. Okay, exercise. So exercise clearly improves our mood, um, can be used as something to help in the treatment of major depression, and the question is, how is it doing that? And one of the answers to that question is actually through the way that exercise shapes our microbiome. How do they shape the microbiome? It depends on what exercise you're doing, okay? So, um, what kind of exercise do you like? I'm curious. I like to lift really heavy. Me too. And I like to run about two to three miles. I ran four miles last night, but I usually run two and a half to three at about a seven-minute-hour pace. Cool. So not too intense, not like too slow, but kind of like a steady pace. Yeah. Um, do you switch up your exercise every once in a while to see if you can get better gains? I daily do different sets and different kind of like body parts, I guess, but I'm, I'm constantly following a program to either intensify or add reps or add weights. Yeah. Yeah. So I'm getting more gains. In fact, I just put up 220; I haven't done 225 in years, but I started like six months ago, maybe four months ago, being like, how many can I do? And I did three. Yeah. It's like, okay, let me see what I can do over the next few months. And like a couple of weeks ago, I did 11 and a half reps of 225. So I feel like I'm back at almost college when I did 15 when I was training football. Yeah. And I feel like I could do more than that now that I have more wisdom and knowledge and nutritional and training and recovery information. So it's amazing to be in your 40s and thriving. Yes. And that's, and I'm actually lifting my heaviest weight in my 40s as well. Yeah. Let's go. Let's go. Yeah, dude, I'm pumped. Let's go get the cameras and let's go lift right now. Exactly. Um, so but I like to play pickleball; I want to make sure I'm doing like some athletic movements also, not just like I'm on a bar, I'm jogging on a treadmill, but it's like, okay, I need to do some pickleball. I like to do ping pong; I like to do different activities; I like to dance salsa. So I'm also making sure that I'm doing lateral movements, not just in the gym, because I know how important that is for mobility, stretching, all these different things, ice tub, sauna, like I'm incorporating as many diverse activities as possible. Well, this is the point, and I don't know that you were intentionally trying to set me up there because we haven't talked about this before, but actually diversity of exercise is actually a relevant idea. Really? Yes. So much we could, we talk about different types of foods have a different effect on our microbiome; different exercises have a different effect on our microbiome. They did this study where they looked at marathon runners, and they identified that there was this one bacteria called *Veillonella* that was disproportionately represented within these marathon runners. So the scientist – this was by the way done, I believe at Harvard in Boston – um, the scientist asked the question, what's the deal with this *Veillonella*? Like, why, why would the runners have more of this specific thing? And the answer was quite interesting: the *Veillonella* was breaking down lactic acid. When we run endurance exercise, lactic acid accumulates in our muscles; that creates muscle fatigue. If you want to be a better runner and have greater endurance, you would break down lactic acid; the microbes are helping. That's interesting. They have another study done by rugby players in Ireland. Uh-huh. All right. And they looked at their microbiome, these rugby players, and they discovered that there was a shift within their microbiome towards actually more anti-inflammatory bacteria that interact with fiber to produce what are called short-chain fatty acids. Wow. Which are the most anti-inflammatory molecules out there. And these short-chain fatty acids, which people may have heard of them – butyrate, acetate, propionate – um, these short-chain fatty acids have healing effects, right? There in your gut, they help to shape the microbiome; they affect the immune system; they affect our metabolism. Wow. And they enter the bloodstream, and they travel all the way to the brain, and they affect the brain, including the blood-brain barrier. That's interesting, because playing, playing football growing up in high school and college, I always felt like I healed very quickly. I felt like I would, like when I get a scrape or a cut or I'd get like a bruised, like it wouldn't really show. And I don't know if that was because I was training in a certain way that was explosive and power and speed that my microbiome, I guess, were helping me recover faster. I have no idea. Yeah, like a rugby player, I know. Well, it's interesting because you think about all the great athletes, for example, in the NFL, and you see these guys, do you know, like Adrian Peterson comes to mind, where some of the recoveries that he had during his career, crazy, were crazy, and they defy like the rules of recovery. Yes. Um, and it makes you wonder if there's something, is that genetics? Is that microbiome? Is that, yeah, are there other factors in play here? But what's interesting is because you have this shift in the microbiome towards these anti-inflammatory molecules, okay, well, I just mentioned that depression has an inflammatory component to it, right? So here we are, and we discover that exercise is actually good for helping our mood. M. And what I'm saying is what's happening under the hood; if you lift up the hood and take a look, is there's this shift in the microbiome. And now you don't even have to change your diet; I mean, I do want you to eat more plants, right? But exercise alone helps you improve your anxiety or stress or depression. Yes. And that, and that shift that's happening in the microbiome is actually helping you to get more from your fiber. So you don't change your diet; you eat the same fiber; now you get more from it. But what if you also changed your diet at the same time that you were implementing this exercise? We did one and two: food and exercise. This is why they synergize so well. So would you say your gut microbiome influences your mood more than anything else? I think that the answer is yes, and the reason why I say that is they have these bizarre studies that they've done where they take people and they inject into them something called lipopolysaccharide. What is that? All right, lipopolysaccharide is produced by bacteria that live inside of us, like *E. coli*. So we've all heard of *E. coli*. Okay. So this is like, they inject a disease inside of us. So they're injecting this thing that you find in *E. coli* into a person's bloodstream. Wow. Okay. And then they track them over the next couple of hours; we're talking about humans; we're not talking about mice right now. Mh. And they see what happens. And here's what they find: number one,

Like all of us, we're depressed. I've been there. Wow. "Below deck, baby, below deck"—that was your drug of choice. So, this was when… how many years ago was this? This was uh, 12 years ago. 12 years ago. So you're… you're in medical school? No, I… so I graduated medical school in 2006, so we're talking about roughly 2012. Okay, so I was a board-certified internal medicine doctor. I finished my internal medicine training, was the chief resident at Northwestern. Wow. And then I moved on to the University of North Carolina. I was on a grant from the NIH and was studying at the school of Public Health—which is like one of the top three schools of Public Health in the country. I was doing that and working during the day as a gastroenterologist in the hospital, and I was miserable. Wow. And um… and my life was in a bad place. Um, I also had high blood pressure, high cholesterol. From a mood perspective, tons of anxiety, high levels of depression. Again, like I just wanted to lay in a dark room by myself under a blanket and be left alone. That's all I wanted to do.

But you had made it; you were at the top of your field, you were an expert, you were, you know, leading a hospital department. So why do you think you were sick, even though you were a doctor? All I know is this: I did not want my own medicine in that moment. Oh, the things you were prescribing to others—the things I was prescribing to others—and that I had been trained by great doctors to do… I didn't want that in that moment. Wow. And because… so the tables had turned. Now I'm the patient, and I needed something to help me. And I tried to… exercise my way out of this. So I'm going to work out harder. I'm a Type A, right? Right. So I go hard. Sass! Oh, hardcore 45 minutes of weight training a day, hit training, cardio. Yeah, jump on the treadmill for either a 5 or a 10K, or jump in the pool (because I was in North Carolina) and do 100 laps. Dang, that's intense. Yes. And triathlon training. I grew stronger… or faster, or whatever athletic measure you want… but um… I still felt unwell. Really? Maybe felt a little bit better… but I really felt unwell. And you had a big gut? I had a big gut. Really? Yeah, yeah. And um… and I needed something to change. And the weird and bizarre thing about it is that I grew up… I come from a humble place in Upstate New York, and I was raised on junk food. Yeah. And this is the way I ate for 75% of my life. And the food that was glorified in our house… how could that possibly be the cause of my problems? The food that brought us love and connection and intimacy and fun and play. Oh yeah, get home from school, play some hoops or Mario Kart, fire up the grill, couple of dogs, right? Like every day, Dre. Yeah, summer barbecue, let's go! It was fun, and I loved it… but it caught up to me. Wow. It caught up to me in my early 30s. And so I needed something to change. And the… and the thing that changed for me was that I eventually looked in the mirror. It was actually by meeting my wife. So, who… like, here we are, you know, uh, more than 10 years later, we have four kids together. But in this moment, we're going on a first date, and she ate very differently than me. Really? Yeah. And I'd never seen anything… how did she eat? We were at… so we were in, you know, North Carolina, right? Um, they didn't have all the diversity back then of foods… well… and you look at the menu, and my wife said to the waiter… she just pulled him aside and she goes, "Can you get me a plate, and on that plate put collards and black-eyed peas and okra and some mashed potatoes." Wow. All right. And so she had them arrange a plant plate, and I was like, "Who are you?" Yeah, yeah. "What is going on here?" I get some steak or chicken or… yeah, yeah, I got my usual pork chop. So look, I'm not saying that's wrong; what I'm saying is that my diet needed an overhaul. Uh-huh. Right there, it needed to be changes. And um… seeing that, she opened my mind, ‘cause she looked amazing. Right? She looked amazing. She seemed to be healthy, have everything going for her, and it seemed to be effortless. And here I am grinding out an hour and a half of exercise every day with a gut… still with a gut… still. Wow. Right? What is going on? Why’d she go on a date with you? So I have no clue. I have no clue. The sun shines on the dogs, you know. So anyway… um… and it just… but it was enough to open my mind. And so there was this one day where… I was going to go to Hardee's and get my usual $5 deal where they can get you like 2500 calories for five bucks. So bad. You know, for about two seconds you feel great, you feel sick, and then you just want to get on some sweats and lay on the couch and make weird noises. So… so anyway, uh… instead, I went home. Look, I'm a single guy in my 30s; I am not going to cook a gourmet meal. Right. Right. So I pulled out a blender and I threw a bunch of stuff in there, and that worked. And I made like a 40-ounce smoothie, and I instantly felt like something that had been missing from my life was in that… in that cup. And um… and it made me… you know, I don't know if you've ever experienced this, but when you feel really unwell, you just want to feel better. Yes. And so that made me feel better. And when… when that happens, it's enough to make you say, "Well, I want to feel that way again." And so I came back the next day and I did it again. And that started the process for me of changing my diet. And once I started to change my diet, the weight melted off my body. Really? My confidence… because I had extremely low self-esteem. But you were at the top of your field as a medical doctor and GI, and running a hospital division… and it didn’t matter. All the degrees… and you could shower me with the degrees and the awards and all these things, and I felt good for a day, and then I went back to feeling like trash. Why do you think you felt so insecure or low self-esteem? I think that… I think that the way that we feel about ourselves is affected by… um… what's going on inside of us. Really? Yeah, I do. Wow. I absolutely do. I think it's more than just… like, there are labels that we can apply, whether or not a person has a clinical condition: major depression, generalized anxiety disorder, whatever you want it to be. But there are also aspects of who we are that are very human that maybe we don't have a label to apply to it, but we all experience it. Right? And that is self-esteem, and that is energy levels. Yes, and things of this variety. And I was in a dark place. And so anyway, making that change completely radically transformed my health. And because… because I had that moment… I'm a medical doctor, and I care a lot, and so I felt like I have no choice; I have to bring this into the clinic. And so I started bringing this into the clinic to treat my patients, and I saw radical transformations among people with irritable bowel syndrome and acid reflux and Crohn's disease and all sorts of colitis. I see these radical transformations. And you get to a point… I eventually got to a point in 2016 where I was like, "This story… like, people deserve to hear this, and it should not be pre-required that you come to see Dr. B as your doctor in order to hear this story. You should be able to hear this no matter where you are." And that's what motivated me to get out there and start doing this. Wow, man.

Do you think it's possible for us to have high self-esteem, high positive energy without exercising and eating only processed foods? I think you'll be… such a fraction of the person that you could be if you were to start to… implement those changes. Wow. Yeah, absolutely. We've only talked about food and exercise first. What's the… what's the third thing? All right, cool. So… um… I wanna… I want to start by saying this: there are these 12 nerves in the brain called the cranial nerves. Okay? And if you actually look—as I did in gross anatomy in medical school—at the skull, clearly we have evolved to really protect these nerves. They come from our brain and they pass through these special sort of channels within the skull, and they basically control everything that really matters: so our ability to see one another, our ability to smell, to hear, to taste, to move our tongue, to talk, to swallow. Right? Like, this is… these 12 nerves impact everything. Impact everything. But there's this one… nerve among the 12 that's like, "Dude, what are you doing here?" It's the… it's like the Black Swan, because 11 of the 12 are just involving basically the brain and the upper neck. But there's this one nerve that breaks off, travels from the brain all the way through the chest, all the way down into the abdomen. The brain comes down… well, I mean, the nerve comes down… comes down… and it's connected… this one nerve… not all 12… no… only one out of 12. Huh? Right. So when you think about how important these nerves are, clearly like these are our priority nerves, and here's this one nerve that has come down to connect to our gut. Wow. And this is called the vagus nerve. All right? And the vagus nerve is absorbing information; it is sensing what is happening within our gut, with our immune system, and communicating that back to our brain. And this is one of the ways I mentioned earlier in the show that the gut has multiple ways to communicate to the brain. We've actually started to cover several of them: one of them is with short-chain fatty acids, another is through the vagus nerve. All right? So these are two of the ways that our gut communicates to our brain. The vagus nerve… um… is fascinating because there's new… there's new technology that's coming out now that shows us that you can actually just activate the vagus nerve and change the way that a person functions. Really? It's… so they call it a vagal nerve stimulator; it's an implanted device. You need surgery in order to have this, and it sends an electrical signal through the vagus nerve, and it goes back to the brain… and it goes back to the brain… and… and by doing this, you can improve a person's recovery after stroke; you can… reduce their exposure to debilitating diseases like epilepsy. Wow. And it's FDA approved for major depression. Holy cow. Yeah. It's now being studied in irritable bowel syndrome, Crohn's disease, and all sorts of colitis. So now we're studying these things in digestive health conditions, not just cognitive conditions, because the vagus nerve affects both. Wow. Okay, so the… the vagus nerve is quite fascinating. We have the ability—using a technique that's completely free and every single listener can apply this to their own life right now—to control the vagus nerve in a number of ways. And the one that I'm here to advocate for is breathing. So deep breathing exercises affect the vagus nerve. All right? Um… the way that we do this is to take 4 seconds in through the nose and then to release for 6 seconds through pursed lips. All right? So you actually are going to be forcing air on some level because you got 6 seconds of a release, slowing it down a little bit on the way out. So this is 10 seconds longer on the way out. So it's not box breathing, but it's not a complete box. Yeah, yeah. Okay, so not holding at the top, breathing out longer than holding at the bottom; you're just breathing in and out longer. You know, different studies look at different… uh-huh… variations on basically the same thing. It always seems to be something on the order of 4 seconds in and at least 4 seconds out. Right? So I'm talking about 6 seconds out just because of this one study that… a little longer. Yeah, yeah. But like, if you do 4 seconds in, 4 seconds out, you're good. You'll be better. It's better than most of us breathing through our chest, you know, one second in, one second out, only in the chest and not deep, intentional, slow, fully oxygenating the body, the brain, everything. Right? All of that and then activating the vagus nerve—that's what we're getting at. Interesting. Yes. So we're talking about activating the vagus nerve by doing this, and you can do this every day, and if you do it for literally 10 minutes, literally 10 minutes, you will notice differences as you start to do this day by day. So if you just do this for 10 minutes a day, just breathing to activate the vagus nerve, what type of improvements can you see? Okay, so we talked about the vagus nerve is this information superhighway connecting our gut to our brain, so we would expect to see improvements in both. Am I right? Yes. Okay, so number one, I'm of course interested in pooping because that's what I work on, right? So I want people to poop, and I want them to have great bowel movements. And in… one particular study, they took people that had irritable bowel syndrome with constipation, so they were constipated people, and they had them do this exercise on a daily basis, and what they discovered is that it actually radically transformed their bowel motility. Right? Their intestines were moving differently, and they pooped more frequently. So they actually had relief from their constipation—not by changing their diet, not by taking a laxative, but by breathing. That was it. That was it. No exercise, no different foods, no dieting, nothing. Just breathing. Just breathing. They pooped better. They pooped better. Now, if you exercise, you'll poop even better. If you eat fiber, you'll poop a hell of a lot better. But… wow… but it's amazing to think… just ponder that… the power that… simply by a breathing exercise… yes… we can alter the physiology of our intestinal system. That's incredible. But we can also affect our brain, and this is backed by studies and science and research. We can post it to the show notes. Yeah, that's amazing. Uh… you can also change the way that our brain works. So by doing this type of breathing, we can improve our focus, improve our memory, improve our cognition, and improve our mood. Wow. This is incredible. Um… I… I do want to talk about… so these are the top three things we can do to improve our mood: food, exercise, breathing… along with all the things you said within each three, which I think are powerful, and I know there's a lot more to it, but that's a great baseline. I do want to talk to you, since we talked about poop… how many times should we be pooping a day? Let's just get right to it. I'm just curious. Like my wife has told me that I'm far too comfortable talking about this topic. Sometimes we're at dinner parties and like… yeah, this is how you should be pooping and how it should look. Yeah, yeah, yeah. She's like, "You're not allowed to talk about bloody bowel movements anymore." Oh my God. So wait a minute… first off, how… how many times should we be pooping a day, and how long does it take after you eat food for it to come out? What's the optimal timeline to know that you're a healthy, functioning human being? I'm so glad that you asked this question… because actually there's a fun experiment that people can do at home… so now… first of all, let me answer the question about pooping. Yes. Um… I'm of the belief that pooping should… should be a… um… it should feel full; it should be a complete evacuation. All right? Okay. It should be a complete evacuation. Um… you should no longer feel like you have to go when you're done. Uh-huh. It should be satisfying, and this entire process, dare I say, should be fun. Like it should feel good. It shouldn't be painful; it certainly should not be painful. It should not be effort; it should feel good, and you should be able to flip that door open and strut out in slow motion, and Michael Bublé—"I'm Feeling Good"—is blasting while… like explosions and slow smoke. Yeah. All right. This is the way that I think it should be for people. Unfortunately, it's not… shocking considering 95% of Americans are fiber deficient. Of course, that plays a role. How often should we poop? The average American poops once a day. If you were consuming an adequate diet with an adequate amount of fiber, you would be pooping more than once a day. Really? Yo, definitely. You would poop probably twice a day, but it's not about the number. So I want to make sure that we not fixate on this because I'm quite sure there will be listeners who will hear this and they'll go, "Something's wrong with me." Hold up. If you are pooping on a level where you have complete, adequate bowel movements, it's satisfying, you have a sense of relief when you're done, and you are not suffering symptoms as a result of your bowel movements, you're in a great place. Wow. And that maybe that's not once a day for you, and that's okay. All right? So there are people who poop every other day, and I would not classify them as constipated based upon that alone. Meanwhile, Lewis, there are people who poop every day and they are clearly constipated. Yeah. And unfortunately, they don't even realize that they're constipated because they say, "I'm pooping every day." You need better bowel movements. If you are not completely evacuating when you go, then that is not… then that is, to me, the first step towards backing up… and backing up as constipation. Wow. How long should it take when you get on the toilet to finish? Um… should it be like, okay, I sit down, it should be like 30 seconds, done, and wipe it clean and move out? Or is it like okay to be there for a few minutes? So for the dudes in the audience, I'm quite sure that many of you have… a habit of bringing your phone into the bathroom and checking your fantasy league or whatever it may be, or playing a video game. And I don't want you spending more than 5 minutes on the toilet if you can avoid it. Um… so the process of pooping should be where we feel a sense of urge—not necessarily urgency, but urge—like, "I need to go; I gotta go. I can hold it if I need to, but it's ready." The time. Yeah, right. And you… and in that moment you are listening to the cues of your body. Right? This is completely natural, and you go into the bathroom, you get into a proper pooping… pooping position, which, by the way, a proper pooping position is not sitting rigidly on a toilet. What is it? It's moving your feet up, so having some sort of… I've got that… you have a Squatty Potty? Oh yeah, do you? I love it, man. I love the Squatty Potty, man. I've had that for a few years. Oh, you're a pooping master; you're a pooping icon. I don't know about that. I was thinking the reason I got it is because I used to be constipated. I used to be like, blocked up. Right? Yeah. I don't know if this is TMI here, but certainly not with me. And I wanted to… and I want to ask you this… for probably… I don't know, 15, 20 years… like it was not every day, but it seemed like it was off and on. Right? I was like, "Oh, man, I'm taking a while to… to go." It's like, you know… you know… I… and I… and here's when it started to change. So what you're telling me at the beginning of this conversation is starting to make some sense. And I started to pull some of this together in the last couple of years, too. I'm curious… about when I was 16, I had eight teeth removed. The… the orthodontist was like, "You've got a small mouth; we gotta open your mouth; we gotta give you braces, but we gotta take out the four wisdom teeth and then four on the sides." Oh, brutal. Right? Yeah, it was miserable. Four weeks of recovery with just ice bags and a freaking helmet to… like, hold it together. Right? It's miserable. Now, as it started to heal, I was just like, "I don't want to go through more pain." I was 16; yeah, football season was coming up. I was going to wear a mouthguard for three months. I was like, "I'll wait till basketball season to put the… the braces on." I delayed it as long as I could. You know, three months turned into 20 years where my teeth started to enclose. I… I couldn't… my back teeth stopped touching, so I only could touch my front two teeth right here. The back teeth… like enclosed… like went reverse; my jaw… so the back teeth did not touch, so I wasn't able to chew properly. So it would get very tiring chewing with my front two teeth. Wow. So I essentially just ate a few bites and swallowed. Yeah. So one… I finally got Invisalign and got braces, and I finally got implants of those teeth so I could actually chomp my food better. Yeah. Once I got those implants in—I still have one more to do—once I got them in, I noticed that I started to use the bathroom better. I was able to chew more fully, chomp more fully, and therefore process better. I was also more intentional about how I was eating and what I was eating and things like that. But I'm curious if you know… if you're just chewing a few bites and swallowing your food as opposed to actually chewing it down, how that affects your… I guess blocked up or constipation levels… and adding that with a processed diet, I'm assuming did not support me with my gut. Right. Yeah. Uh… there's multiple different factors there. It's interesting what you're describing with your teeth because this is what a lot of older people deal with on a routine basis. Really? Yeah. And they… and they struggle to be able to chew their food. And because they can't chew their food, they opt for simpler foods that are pre-digested in a way. Really? Which are ultra-processed foods. It's a lot easier to eat ultra-processed foods. There's quite a bit of data actually around eating rate—how fast we eat. By the way, this is something that we're looking at at Zoe… Zoe is a company that we… are running the world so hard, just nutrition science study right now, and I'm the US medical director. And so with eating rate—how fast you eat—it's highly compelling that… foods that require us to slow down actually are beneficial to our metabolism. Interesting. Yeah. And you could take the exact same food and serve it two different ways: one of which you can just scarf down, or the other one requires you to actually chew your food. And the one that… requires you to chew your food… that's less pre-digested… actually is better for your body metabolically. Really? Yeah. So like… versus… what about a smoothie? Uh… in a perfect world… in a perfect world, you would eat a salad. You want to make a smoothie, or you make a smoothie… but I'm here advocating for smoothies because they're delicious and they're a great way to still get fiber, phytochemicals, polyphenols into your diet with a diversity of plants. So… and then you can have your… your salad for lunch. Like you're not going to… sell it at every meal, honestly. Yeah, exactly. Wow. So you're saying nut butter versus… uh… almonds… it's better than the almonds? 100%. Why is that? Um… I think there's a couple of things. So part of it is the… the food itself. It's not like… food is more than just calories and nutrients and macros. Um… there's a structure to the food, and we call it the food matrix. And an intact food matrix is, generally speaking, the preferred way to… to consume our food. So basically what that means is less processed. Wow. Yeah. So if it's pure… even if it's like a whole food, but it's pureed or… or processed, right, or crushed down or whatever it might be… it's better to have the whole food by itself than the processed version or the crushed-down version when… when possible. But like, I'm not here to make it sound like I don't like almond butter or peanut butter. Um… there have been some interesting studies about if you take the… the exact same food and you cook it… if you cook it, it actually has a different effect on the microbiome. So like, for example, you take… kale… and maybe you would steam the kale to soften it up and things like this… by steaming it, you're actually changing the food a little bit. It's not a bad thing, and it'll have a slightly different effect on your gut microbiome than that raw… uncooked kale. So yeah, there's a lot of interesting stuff there. What… what is more effective or more efficient: the raw, uncooked vegetables or cooked—steamed, sautéed—vegetables? I think when people are changing their diet, it's better to give your gut an opportunity to adapt and to gently ease into it. And cooked food, or like, you know, these… like things that are kind of broken down already, they're a lot easier to… to digest than like the raw foods are. So like, going raw food only… to me, I don't really advocate for that. That… yeah. All right, so bowel movements. Yes. So… uh… I prefer for people to have a natural bowel movement in 5 minutes or less. You shouldn't have to strain to go. In a perfect world… um… it should come out quite naturally. You get your business done, you get up, you walk out the door. Don't sit there. Don't sit there because blood gets pulled down into your pelvis when you're sitting there in that position, and it actually fills the hemorrhoids. And we have an epidemic… I mean, I hate to say this; I feel like we've been talking about a lot of epidemics here today… we have an epidemic of hemorrhoidal issues. What is hemorrhoids? Um… hemorrhoids are the most… uh… attractive… concept out there. So… um… these are basically like veins that carry blood, and they exist right around our bottom. Now I know I should have an answer for why did we evolve to have hemorrhoids, and I do not. I don't honestly know why we evolved to have hemorrhoids, but we did. They're there. All right? And when we… when our bowel movements change—whether that be constipation or diarrhea or straining to go and bearing down and pushing—we are actually driving blood down into these beds of… of tissue; these hemorrhoids. They get engorged; they get enlarged and then can cause trouble. So they can cause bleeding; they can pop out; um… they can itch. So there's a number of different things. And statistically, 50% of Americans who are age 50 have hemorrhoidal issues. So… so you heal those hemorrhoids… you can make dietary changes that will certainly improve them substantially because they… and flow a little bit, so maybe they wouldn't be completely non-problematic because they are a part of our anatomy. So when you change the anatomy and you have… got it. But anyway… so that's the reason to… to not spend too much time on the toilet. So… and so if someone is having one of those three… I guess you said diarrhea, constipation, and like… straining… straining like… to push through the… go… right? If they're experiencing that occasionally or frequently, what are the main causes of those three styles of unhealthy poop? This is a huge conversation. I mean, like, I have… might take a day to… hold… yeah… I have like courses that are multi-hour courses that I teach on this… on these… each of those topics. But… but if we were to say, okay, let's bring it back to like, what is the thing you can do… the answer is fiber. Fiber. Because the… the… the power of fiber… again, 95% of Americans are deficient in fiber. What's unique and special about fiber? One of its superpowers, beyond feeding and fueling our gut microbiome to create short-chain fatty acids, is that it's the only thing that I'm aware of that can fix both diarrhea and constipation. Fiber. And bring it back to the middle. So it gives your stool form; it gives you that glorious soft but formed bowel movement that we're striving towards. And when it's soft and formed, then it comes out a lot easier; you don't have to strain to go. So we are addressing all of the issues that you just described. So when you have… when you have hard… when you have hard poop… or I can see you blushing just a little… or you have… I guess I don't know what the word would be… like… uh… not continuous… or it's like… just… yeah… loose… loose… or comes out… yeah, yeah… what does that mean? Is this mean you don't have fiber? If you have like really… all right… hard poop… or like it's not continuous… what we do know is… what we do know is this: it actually brings me back to a question that you asked earlier, which is… how long should it take for us to poo? Yes. Right? If it's faster, that's typically associated with… with loose stool… like diarrhea, because you have faster transit; you're moving through. Yes. And when it's slower, that's associated with constipation. Uh-huh. And both of these things are actually associated with changes in the microbiome. So the microbiome is a player for sure in our gut motility and whether or not we develop diarrhea or constipation. Okay. And we can actually do a simple at-home exercise to measure this and determine what our gut transit time is. And that is… so we, at Zoe—this is actually a study that we published in one of the top gastroenterology journals on the planet called *The Gut*—and um… basically what we did is we had people eat blue muffins. Mmm… these blue muffins… the food dye will show up in your poop. Uh-huh. So you can see when it comes out. So you can see when it comes out… how long time it… but you time it. Yes. And most people are like… either they're pooping 24 hours later or 36 hours later… wow… or up to 48 hours later. And all that is normal. Okay. All that is normal. But if you see that blue in less than 18 hours, you've got fast transit, and typically you're going to have diarrhea. And that's actually… that's not good; we don't want that. Okay? So that's a lack of fiber many times; that's a lack of fiber. Uh-huh. Um… or you may see very slow transit where it's coming out like more than two days later. Right? And that… that's not good either. That's not good either. So all of these things are actually correlated—not just to our microbiome because they are—but they're also correlated to metabolic parameters. So… um… like, for example, there's this thing that we use as physicians to predict a person's risk of cardiovascular disease, like heart attack. So this is like a 10-year risk score, and believe it or not, like your bowel transit time in this study was correlated to your cardiovascular risk. Wow. So… so it's worth us paying attention to these things. So having healthy poop is a huge part of living a healthy life. I think so. And I think that like… the… the thing that's interesting about… about poop is that… we ignore it. We ignore it because it's like… we've stigmatized it. But if… as a gastroenterologist, you look at your poop every time… most of the time. Yeah, yeah, yeah. I guess kind of proud. Kind of proud. We're in a good place. That's good. Yeah. Um… well, it's important to pay attention. I guess you don't… to stare at it, but it's like… it's important… like you have to be creepy. Okay. Yeah, flush. See it as it goes down and… all right, I'm doing the right things. You don't have to be creepy about it, and you don't have to obsess about it, but you should… not putting your hand in there and checking it out; you're not doing weird stuff. Yeah, please don't do weird stuff. But um… I do think it's worthwhile to take a look and understand where you're at. And there are these… seven different… uh… measures of stool called the Bristol Stool Score. Interesting. Okay. So… and they're… they're individual pictures that allow you to see like… what… you know… "Hey, my poop looks like this." All right? And some of them are diarrhea, and some of them are constipation, and some of them are right in the middle where you want to be. That's a Bristol 4. Bristol 4 is the fantastic, glorious bowel movement. Okay. Okay. So… and the… the… the thing that's key from my perspective, because this correlates to our gut microbiome, and if it correlates to our gut microbiome, then it also correlates to our digestive health, our metabolic health, our immune health, our… our cognitive health… because of this, we should be looking at this. Um… so I think it's important for people to know… so you can at least know, "Hey, is this not a Bristol 4? Is this a Bristol 1 or 2, which is constipation? Is this a 6 or 7, which is super loose and watery, which is diarrhea?" Because if that's where you are, then we need to make some changes in order to get you to a better place. And a lot of it comes down to adding more fiber to your diet. If you add more fiber to your diet, for the vast majority of people, they will actually see substantial improvements in terms of those bowel issues. Wow. Now I don't want to sit here like… there are people that have, you know… um… some sort of medical issue. Sure. It's more complicated in those people, so let's not make it too simple here. Right. Right. Right. Right. Wow. Fiber… fiber is one of the keys it sounds like. Now, how do you know… what are the… I guess what are the main symptoms of having a leaky gut? Well, we've started to touch on this. Yeah. So a leaky gut… again, it comes back to this single layer of cells, the epithelial layer, and when it's breaking down, it's because of things that are happening within the microbiome, and it's creating opportunity for things to get into the bloodstream or across into the immune system… system that aren't supposed to be there. When a person has a leaky gut, there can be a number of things, but I think the first thing you're going to feel is a loss of energy. Okay?

My way of thinking about this condition has changed many times during my career. The way I think about and treat IBS, yeah, yeah, about thinking about and treating IBS, right. Now there's a more holistic view, which is a good thing. It's not just, "Here's a drug, or here's this thing," yeah, yes. It's not just a digestive disorder; it's a disorder of the brain and gut axis. Interesting, yeah.

Because I've heard about people struggling to go to the restroom at different times if they feel unsafe, or if they're in an unhealthy relationship, causing gut issues. Is that connected to the nervous system? Not feeling safe because of the environment or out-of-alignment relationships—does that impact the digestive inner workings? Is that all play in? 100%, really? 100%. Do you think IBS is more of an emotional challenge? I think it's a disorder of the brain-gut axis. Interesting. I think it's more than just one or the other; I think it's both. So we have to incorporate both into our concept of that. But, um, let's start with a simple example: a person's about to go on stage and give a speech. They have anxiety; they feel a flutter in their stomach, start to feel nauseous, maybe it builds towards cramping abdominal pain, and maybe they have to run to the restroom. Wow, right? When I was in medical school, on test day, there was a line out the bathroom door. It was disgusting right before. When I played football, man, I had to go 5-10 minutes before the game started. Yeah, you try to go an hour before, but then the nerves or excitement would be like, "I gotta go now!" Yeah, right before the game, I'm like, "I gotta go!"

Let's describe exactly what's happening there. Basically, it's the brain-gut connection. Now the brain is taking center stage; the gut becomes secondary. The stress of the moment activates the sympathetic nervous system. Wow. The sympathetic nervous system is the opposite of the vagus nerve; the vagus nerve is our parasympathetic, our rest-and-digest, relaxed state. The sympathetic is, "I'm about to run into a football and try to knock someone's head off," right? You're getting charged up for a fight, or to run away from a saber-tooth tiger, or whatever. That's our sympathetic nervous system. As part of that stress response, good things happen: you get an adrenaline surge, feel powerful, and can do superhuman things. But there's a sacrifice: your gut. The brain releases corticotropin-releasing hormone, or CRH. CRH sets off this inflammatory cascade, and downstream, it negatively impacts the gut microbiome. It affects motility and directly affects the microbes; there's a shift within the microbiome. And here we are, you gotta go to the bathroom. Wow. You'd think in a fight-or-flight moment your body would suck it in so you could run away, right? Some people do; some get very constipated under stress. But we're talking about acute stress, different from chronic stress.

What do you do if you've been exposed to trauma, and it lives in your unconscious mind, causing daily chronic stress because you haven't healed that emotional wound? What happens? People get IBS, Crohn's disease, colitis. I've had many patients. 100%, wow. Because what I'm giving you are the diagnoses, but the root cause is a damaged gut, with leaky gut. The symptoms, or diagnoses, are the damaged gut, but the root is a lack of healing from emotional trauma. I've had many patients; these are my proudest moments as a doctor, to be completely honest. My proudest moments aren't getting people to change their diet; it's taking someone who's been to six or seven doctors and isn't getting better, even with medication. You build a doctor-patient relationship—not one visit, but four, five, six visits—and they tell you something from their past still affecting them today. My role isn't to fix that issue, but to bring awareness so they understand these aren't separate issues. Wow. Once they discover that, treatment is next-level because they turn their attention to what they've been avoiding or ignoring. They have a healthcare professional (not me) to help heal that wound. When they heal that wound—these are people doing 30 different plants, exercising, deep breathing exercises, still messed up—gut's still messed up, Dr. B, I've done everything your book tells me to do, I'm still messed up. Okay, once we discover this, healing is a rocket ship; it transforms them completely because everything is right, but the rocket ship is chained down. Wow. It's trying to go off but can't because of these chains, and you gotta break the chains holding them back—their history of trauma. Man, isn't this fascinating? You can do all the right things physically, but if you don't heal emotionally or psychologically and allow your nervous system to feel safe, you can't take off as a human being. 100%.

That is fascinating. I believe learning to face yourself and address emotional, psychological, or memory wounds, processing those things—which can take time—and healing them emotionally will set you free physically. I think this is the missing piece many haven't heard and need to hear. Wow. It's almost like doctors should have therapy training, to implement that process. You couldn't be trained therapists, but with some training, it could elevate healing. I believe in a team-based approach to healing; one person can't do everything anymore. You need a team of competent people you trust and have faith in. Gosh. I want to give a shout-out to my mentor at UNC, Doug Drossman. He's the founder of Rome I criteria for IBS, and wrote the book on it. It’s called the Rome Foundation, a group of scientists who met in Rome, Italy, and put together this idea of what IBS is, back in the 80s. Wow. That was Rome I, and I think they're on Rome IV now. He organized and led this, created this diagnosis. I worked in his clinic; the hospital hated us. We saw two patients in half a day; most gastroenterologists see two patients in 15 minutes. Really? Yeah. We spent hours with these people—the ones bouncing from doctor to doctor and never getting better. The system was failing them because you can't just use a pill for everything. Wow. You can't just make a diagnosis and fix everything. At some point, someone needs a holistic view and to see the complete person, that we're more than just one set of symptoms. And that's what we did. He was a professor of both medicine and psychiatry; I'd call him a maverick. Back in the 80s and 90s, he was making connections, like, for example, a history of sexual abuse in childhood connecting to the manifestation of digestive disease as an adult. Wow.

I’ve talked about dealing with sexual abuse as a 5-year-old, feeling unsafe and clenched, always looking out for who's going to attack, abuse, or take advantage of me, even in non-sexual settings—school, sports, whatever. I believe that was a big part. Four or five years ago I started diving deeper on sexual abuse healing (I started 11 years ago but didn't fix the teeth and still ate poorly). Putting it all together four or five years ago—fixing teeth, intentional eating, healthier eating, healing trauma on a deeper level—allowed more freedom within my body, peace and harmony. Someone asked me this morning at the gym how I felt, and I said I’m feeling peaceful, loved, abundant, grateful, and harmonious. It's how I feel. Sounds amazing. But it's been willing to face incredible amounts of pain within myself, addressing it consistently for the last four and a half years, almost weekly, facing and processing the pain to create meaning, processing shame, guilt, insecurity, and whatever else I was holding onto psychologically, emotionally, physically from different traumas of life, allowing myself self-love without shame anymore. It's been the most challenging but liberating and freeing process, a journey that will continue. I feel better, my gut has reacted better, and I feel like I can only improve from here. I'm so glad you, as an expert and medical doctor, talk about healing emotional traumas; sometimes that's what allows us to elevate our physical potential. People like you can change millions of lives because you speak openly about a difficult topic, requiring courage and putting yourself out there. I appreciate that. You said you felt "tensed up," "clinched"—it's no coincidence that constipation is a manifestation of that trauma. That clenched feeling—you truly are. Yeah, constantly. Yeah. I don't attach that to myself anymore, but in my youth, teens, and early 20s it was a clenched feeling, like I was ready to fight at all times, waiting for someone to take advantage of me, wanting to trust and love the world but waiting for someone to take advantage of me. Yeah, it wasn't a relaxed state of being. How can you trust when you're a vulnerable 5-year-old exposed to that? That's really hard, and as adults we struggle to overcome those experiences. But the word "clinched"—you intended it figuratively, but it's literal. It is literal, and it caused digestive pain; it was hard to go to the bathroom, sitting there for 20-30 minutes. But, like you said, going back to breathing, activating breathing for 10 minutes a day will relax your mind, nervous system, body, and connect your gut so you can process everything better. You add exercise, you add food, but the fourth thing, I'm hearing you say, is healing emotional wounds, healing trauma. You could do the first three—food, exercise, breathing—but until they heal the trauma, many patients struggle with their gut. I don't think this is everyone, but for people with something from their past they're still struggling with—maybe repressed, maybe not thinking about it, but it's there—if you have something like that, I want to bring awareness that you can't hide or put it aside; it's continuing to affect you. To be the best version of yourself, reach out for help and address it directly. Wow, this is beautiful, man.

I have so many other questions, but I think a lot are in one of your books. You have so much content. People should check out your website. What's the main place to send people to learn about your books, programs, information? You can find me on social media; I'm the Gut Health MD. You can come to my website, theplantfedgut.com. I'm proud of my email newsletter; we have a large community. My favorite way of communicating isn't on social media; it's through my newsletter. I can break down studies the way I like. I'm signing up. Thank you, dude. I'm the US medical director of Zoe. Zoe is running the world's largest nutritional science study. If you sign up, we send you a kit: a microbiome test, continuous glucose measure, and blood fat test. We combine those factors to give you a personalized dietary plan. I'm proud that Zoe ran a randomized control trial; the results will be published in Nature Medicine. I don't know exactly when, it depends on when the show airs. Sure, sure. That's literally the top journal on the planet; that journal never takes randomized control trials. I think they took ours because it's a groundbreaking study. But nonetheless, we're honored. What did the study reveal? People in the US were randomized to either do the Zoe program or follow US dietary guidelines. We can all find stuff in the guidelines to disagree with, but if you actually follow it, most of it is sensible advice. What's the main philosophy? Consume enough fiber, add more fruits and vegetables to your diet. Grandma said that, yeah. There's stuff I may disagree with, but the majority—you know what, you got probably 80% of it right. Sometimes Grandma said, "Finish your pie," you know. That's because she loved you. That's because she loved you; it wasn't because she was worried about your health. Exactly. Yeah, and she wanted you to love her back. Exactly. Yeah. But anyway, we're not comparing to eating Twinkies, right? We're comparing to a real diet recommended by our government. So in this study, people on the Zoe program lost multiple centimeters off their waist, reduced visceral fat, lost weight, lowered triglycerides, and improved their gut microbiome. The part I want to talk about, relevant to this conversation, is that they had substantially more energy, better mood, slept better, and improved hunger; they controlled their appetite. They got all these benefits, but the cool part is that people most compliant with our program—some people don't do it, right—but if you actually do it, you get everything I just described, intensified. You double the number of centimeters off your waist, wow, right? By actually doing the program, you reduce cardiovascular risk factors; you lower blood pressure, apoB, LDL cholesterol. I think this is why Nature Medicine published our paper: we looked at people most compliant with Zoe versus those most compliant with government guidelines. Are you actually doing it? When we compared those two, Zoe dominated. This personalized plan, specific to you—it's not the same for everyone—outperformed what our government considers our ideal diet. Do this for everyone. Zoe takes three different measurements and tells you what your body, gut, blood, and genetics should be doing for you. We break it down, and it’ll be different for everyone. 100%. You could do it with siblings. I've got three older siblings—a brother and two sisters. If you all did this, you'd discover you're different. A big part of the difference is your microbiome—it's completely unique to you. No one on the planet has a microbiome like yours. You might share similar genetics, but your response to food is different because you have all these other factors that are different, and we can see that. We can look at your blood sugar, blood fat, microbiome, give you feedback, and empower you with an understanding of your food. There's no food that's off-limits; this isn't about restriction, it's about abundance. Wow. It's about understanding your food and how to properly eat for your unique biology. That to me is exciting. Wow.

How can people get access to this or try this? If you want to check it out, go to zoe.com. I'll be there because you'll find a sweet little gift from me: a 10% off ticket. Nice. And you can use that code to save a little cash if you decide to go for it. Amazing. And we have a podcast, too. By the way, I've seen it. Yeah, it's in the top of the charts in the health section. I see that. Yes. It's always competing with me; I'm trying to get ahead of that all the time. You know, you have an amazing, diverse podcast. I love what you do, and we're science-oriented, exclusively, with a heavy focus on nutrition, but a lot of other things, too. People can check that out, too. You guys are doing awesome. zoe.com, will be. Also theplantfedgut.com; check that out. The Gut Health MD on Instagram, Facebook, and social media. This is powerful stuff, man, and the more knowledge and wisdom we have around this information, the more we can test it, try some of it today, and see how it impacts our mood, health, and well-being; it'll make us better human beings. I'm so grateful, and I want to acknowledge you, Will, for dedicating the last 20 years of your life to understanding this, expanding your knowledge, doing all the studies and research, but also taking a big risk and leap of faith when you got sick 10-12 years ago, saying, "Let me see if there's other information I can gain outside of my medical training; let me try new things; let me take this from a first principles approach; let me see if there are other ways I can heal myself first, so I can help others heal as well." I want to acknowledge you for that, man, because I think there are a lot of people sick today, like you talked about, and unless people get this information from you or other people like yourself, people are going to be very sick over the next 5-10-20 years, and it's going to take big wake-up calls for them until they make a change. I hope people spread this message and share it with a friend today and help anyone, even if they don't seem unhealthy physically. Send them this episode—video or audio—to get people educated and informed on how to be healthier and impact the people in their lives more. It just feels like people are sicker now more than ever. Posing thought. Yes, that sounds very pessimistic. I get it; I understand that people would feel that way. I'm very optimistic. That's good. Here's why: there's a revolution taking place in science. We didn't know anything about this microbiome stuff until now. Wow. Now we have the ability to not just look at it, but manipulate it. We've proven that with the Zoe study I just mentioned, the randomized control trial. We have the power to manipulate it. The choices you make today will have an effect on your microbiome by tomorrow. For the listeners at home, be optimistic that you can make a small choice, and these small choices may seem trivial in the moment, but guess what? If you do that again tomorrow and the next day, this small choice becomes a massive and powerful choice for your health. Don't wait until you have a problem; do it now. That's incredible, man.

I want to ask you two final questions, Dr. B. One is, I call it the three truths. Imagine a hypothetical scenario: you get to live as long as you want, but it's your last day on Earth. You get to see your family grow up, have a beautiful life, continue to create in science and research, write more books, speak, and whatever you want to do; you get to live your life fully, but it's the last day. For whatever reason, in this hypothetical scenario, you have to take all your work with you; every recorded conversation is gone, every book, podcast, post—anything you've ever published is gone; we don't have access to your information anymore. But on your final day, you get to leave behind three lessons to the world, three truths that would be your truths. What would those be? I'm gonna start with the obvious one from this episode: increase your fiber intake and add 30 different plants to your diet. All right, so let's get that out of the way. I want to move into the part I'm excited about: number two, invest in human connection. I think it's so important. And number three, make sure you make time for your family, the people you love. Yeah. Because at the end of the day, all these things—the money is seductive, it's attractive—but it's love, it's relationships, it's family that really make us feel full. Mhm. Final question: what's your definition of greatness? Thriving in everything you do. But there's all sorts of interesting intermittent fasting regimens. One thing that fasting does is boost autophagy, a house-cleaning process within cells, killing zombie cells. Well, that's a whole separate thing, but this is more inside the cell, the accumulation of debris that contributes to age...