The Hidden Connection Between Gut Health & Mental Health That Therapy and Drugs Cannot Fix - Dr. Mark Hyman

Open the Podcasts app and search for The Doctor’s Farmacy. If you’re viewing this site on your phone, you can just tap on the

Tap the subscribe button and new shows will be added to your library.

If you’re using a different device, our show is available on the following platforms.

View all Platforms
Episode 879
The Doctor's Farmacy

The Hidden Connection Between Gut Health & Mental Health That Therapy and Drugs Cannot Fix

Open the Podcasts app and search for The Doctor’s Farmacy. If you’re viewing this site on your phone, you can just tap on the

Tap the subscribe button and new shows will be added to your library.

If you’re using a different device, our show is available on the following platforms.

View all Platforms

Our global mental health crisis is growing at an exponential rate, with over half a billion people suffering from depression and anxiety; it’s time we rethink our understanding of the underlying root causes of mental health challenges.

From treating thousands of patients, I’ve learned that depression is not in your head. It’s in your body. More specifically, your gut. When your gut is unhealthy and inflamed, your brain is unhealthy and inflamed. In Functional Medicine, we know that the gut and the brain are intimately connected and that the health of one directly influences the health of the other.

In today’s Health Bites episode, we’re diving into the gut-brain connection and sharing Functional Medicine tools to support your gut health and, as a result, your mood and mental health.

This episode is brought to you by AG1 and Rupa Health.

Get your daily serving of vitamins, minerals, adaptogens, and more with AG1. Head to DrinkAG1.com/Hyman and get 10 FREE travel packs + FREE Welcome Kit with your first order.

Streamline your lab orders with Rupa Health. Access more than 3,000 specialty lab tests and register for a FREE live demo at RupaHealth.com.

I hope you enjoyed this conversation as much as I did. Wishing you health and happiness,
Mark Hyman, MD
Mark Hyman, MD

In this episode, you will learn:

  1. Our global mental health crisis
    (2:45)
  2. The gut-brain connection
    (4:18)
  3. The story of Marks's broken brain
    (5:15)
  4. Features of the gut-brain axis
    (8:57)
  5. Gut hormones that send signals to your brain
    (10:06)
  6. Role of the gut microbiota in mood and mental health
    (12:24)
  7. How stress negatively impacts our gut microbiome
    (20:14)
  8. The link between leaky gut and poor mental health
    (21:41)
  9. The Functional Medicine approach to fixing the gut
    (25:56)
  10. The 5R Program for fixing your gut health
    (30:09)

Show Notes

  1. Getting To Know Your Gut Bugs: Akkermansia Muciniphila
  2. 10 Day Reset
  3. The Human Brain in Numbers: A Linearly Scaled-up Primate Brain (Frontiers in Human Neuroscience)
  4. Gut feelings: the emerging biology of gut-brain communication (Nature Reviews Neuroscience)
  5. Burden of anxiety and depression among hospitalized patients with irritable bowel syndrome: a nationwide analysis (Irish Journal of Medical Science)
  6. Vagus Nerve (Cleveland Clinic)
  7. The role of the vagus nerve in appetite control: Implications for the pathogenesis of obesity (Journal of Neuroendocrinology)
  8. 20 Things you Didn’t Know About the Human gut Microbiome (Journal of Cardiovascular Nursing)
  9. Neurotransmitter modulation by the gut microbiota (Brain Research)
  10. The Role of Gut Microbiota in Anxiety, Depression, and Other Mental Disorders as Well as the Protective Effects of Dietary Components (Nutrients)
  11. Exposure to a social stressor disrupts the community structure of the colonic mucosa-associated microbiota (BMC Microbiology)
  12. Marital distress, depression, and a leaky gut: Translocation of bacterial endotoxin as a pathway to inflammation (Psychoneuroendocrinology)
  13. Zonulin, a newly discovered modulator of intestinal permeability, and its expression in coeliac disease (Lancet)
  14. Prevalence and identification of neuropsychiatric symptoms in systemic autoimmune rheumatic diseases: an international mixed methods study (Rheumatology)
  15. Mood disturbance during experimental endotoxemia: Predictors of state anxiety as a psychological component of sickness behavior (Brain, Behavior, and Immunity)
  16. Discordant patterns of bacterial translocation markers and implications for innate immune imbalances in schizophrenia (Schizophrenia Research)
  17. Effects of ultra-processed foods on the microbiota-gut-brain axis: The bread-and-butter issue (Food Research International)
  18. A high-sugar diet rapidly enhances susceptibility to colitis via depletion of luminal short-chain fatty acids in mice (Scientific Reports)
  19. Diet, Sleep, and Mental Health: Insights from the UK Biobank Study (Nutrients)
  20. Feed your microbes to deal with stress: a psychobiotic diet impacts microbial stability and perceived stress in a healthy adult population (Nature)
  21. Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials (Nutrients)
  22. The effects of probiotics on mental health and hypothalamic-pituitary-adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers (Nutritional Neuroscience)

Transcript Note: Please forgive any typos or errors in the following transcript. It was generated by a third party and has not been subsequently reviewed by our team.

Dr. Mark Hyman:
Coming up on this episode of the Doctor’s Farmacy over the last 30 years, I’ve learned that depression is mostly not in your head, it’s in your body. When your gut is unhealthy, your brain is unhealthy. Now, conventional medicine views these two things as completely separate and unrelated. Functional medicine. We know the gut and the brain are in connected and that the health of one directly impacts the other. Welcome to Doctors’ Farmacy. I’m Dr. Mark Hyman, that’s Farmacy with Anfa Place for conversations that matter. And today we’re doing another special episode of Health Bites and we’re talking about something really, really important, which is the role that your gut microbiome plays in your mental health. I’m going to say that again. The role that your gut and your microbiome, essentially the bugs in your gut play in your mental health. This is an enormous topic, almost completely ignored by medicine.
Although there are a few places like at Harvard where they’re talking about this, Uma Naidu at Harvard’s Department of Nutritional Psychiatry. But it is a big issue that we can address and we need to address because I’ve seen this in my practice over and over again. Now, why is this so important? We have a mental health crisis globally, 300 million people are suffering from anxiety. 280 million people are suffering from depression. Now, from treating thousands of patients over the last 30 years, I’ve learned that depression is mostly not in your head, it’s in your body. When I treat patients’ gut issues, and this is something I just discovered almost by accident, their mental health would magically get better, but it wasn’t magic, it was science. I just didn’t understand at the time. It’s not magic. Gut dysfunction is not the only cost of our mental health crisis.
There’s a lot of things that are driving it, but it’s a major factor that’s often unaddressed. Now, when your gut is unhealthy, when it’s inflamed, your brain is unhealthy and also inflamed. When we fix the gut, then brain health, mood, memory, focus, and mental health all improve. Now, why is this important? Inflammation is a huge driver of most of our mental health issues from depression, anxiety, autism, a, d, D, even things like Alzheimer’s, schizophrenia, bipolar disease, all linked to inflammation in the brain. And where’s this inflammation coming from? Obviously our diet, but also from our microbiome. And I learned this early in my medical practice. In fact, one of my early books called The UltraMind Solution, a deep dive into the way the body affects the brain, including the gut and the microbiome. Now, conventional medicine views these two things as completely separate and unrelated.
And typically if you have GI symptoms, you go to the GI doctor, a gastroenterologist, and if you have mental health issues, you go to a psychiatrist to help with balancing your mood. They prescribe different drugs for each condition instead of understanding the root cause and treating that. Now we’re going to talk about how this works, why it’s important, what the science is. And some of my clinical case studies, which are quite compelling now in functional medicine, we know the gut and the brain are inly connected and that the health of one directly impacts the other. So you can’t fix the brain without fixing the gut, and you can’t fix the gut without fixing the brain. So it’s bidirectional. It’s not mind, body, body, mind, body, mind, mind, body. It’s both right? When we do that, and I’ve done this in thousands of patients and the studies back this up, and more and more data’s coming out like Chris Palmer, du and psychiatrist from Stanford, integrative psychiatrist, functional psychiatrists are all seeing this.
And data is really exploding on this. When I wrote the book 15 years ago, there was data, but it was limited, but I saw it and I saw the kind of whispers in the wind, let’s say the sort of tea leaves. And I was like, okay, this is really something. And when I started to do this, my patients, and when we do this now, we see profound improvements in mood and obviously digestive health and all other areas of health. So gut is just linked to everything. So fix the gut, fix the body, fix the gut, fix the brain. I know how powerful this is and how powerful functional medicine is for fixing depression because I also had it myself, and it wasn’t because of something that had to do with my psycho-emotional health, but my physical health, my brain literally broke one day in 1996.
I felt like I had a d, d depression and dementia all at once. I saw lots of doctors, psychiatrists, no one could find the cause, although they wanted me to take Prozac for my symptoms and no one could agree on the diagnosis. Some said I had depression, others said I had chronic fatigue, and in fact I did have chronic fatigue. And I started to deep dive into the literature and I consulted with other doctors and scientists, people on the leading edge of medicine, and I started to do some experimentation. And when I came to understand that it wasn’t just one thing that caused my brain to break, it was accumulation of a lot of things, diet stuff, stress, environmental, toxins, like mercury was a big factor. My gut was just a mess. In fact, that’s what happened. I had mercury underlying all this, and then one day I got some kind of gut infection up in Maine at a camp and then boom, my gut was off and it didn’t get back on track for many years until I figured out how to fix it.
And all that leads to inflammation. So rebalancing my gut microbiome, getting rid of the mercury, it was messing up my gut because Mercury interferes with gut function. It was the key to getting my brain and health back. I also saw this with so many of my patients. I had a woman who had severe OCD. She wouldn’t clean up her house for years because she didn’t want to move things around on the floor. Looked at her health and her biology and tried to see what was going on. And in functional medicine, we just take out the bad stuff, put in the good stuff. So I saw she had a lot of bad bugs in her gut, a lot of overgrowth of yeast, and I gave her basically an antibiotic and antifungal that was designed to kill those particular bugs. And literally overnight, her OCD went away and she was able to clean up her whole house after decades.
I also had a little girl who was a sweet little girl, nine years old, but was a terror. She would get kicked out of school all day on the bus ride home. They’d have to stop the bus 10 times. She was terrorizing her little sister, tearing out pictures of the family, just kind of little nuts. I did testing and she didn’t have any gut symptoms, but we found really high levels of bacterial overgrowth and bad bugs in her gut and yeast overgrowth. And again, I gave her an antibiotic in antifungal and literally overnight she turned into this beautiful sweet little girl. So that made me think, oh my God, there’s a whole untapped world here that we’re missing of how to help people who not only have physical health issues, but also have mental health issues. So today we’re going to dive deep into the gut brain connection.
We’re going to share some functional medicine tools that will help support your gut health and obviously your mood and mental health too. So what is this gut brain connection exactly? Well, let’s go into the science. The human brain contains approximately a hundred billion neurons, brain cells, nerve cells, right? The gut also has a nervous system. It’s called the second brain, also known as the enteric nervous system. Enteric just means gut, fancy medical word, and this contains get this 500 million neurons. So there’s five times as many neurons in your gut as in your brain. Now, there’s a bidirectional highway between the brain brain and the gut brain, and this is called the vagus nerve, and it links our enteric nervous system with our brain and their central nervous system, and it’s sending and receiving signals all the time. So whatever’s happening in your brain, mood, stress, emotions, impacts your gut function and what’s ever happening in your gut impacts your brain function, right?
Mind, body, body, mind. We talk about this. I felt sick to my stomach. I have gut feelings. Maybe you’re so nervous you had to run to the bathroom, right? This is the gut brain connection at work. There was a study that looked at more than 1.2 million hospitalizations for irritable bowel and 4,000 hospitals. And people with IBS or irritable bowel syndrome had three times high risk of anxiety, two times greater risk of depression, and at two times greater risk of suicide ideation, meaning they were thinking of suicide versus the general population. Now, we used to think that anxiety caused IBS, but now we know it’s the other way around and a little bidirectional. So think about that. It’s not really the stress or anxiety or mental health issues that’s causing irritable bowel. It’s a change in the microbiome and the irritation, inflammation to the gut lining and the enteric nervous system that feeds back to the brain.
It creates an irritable brain. So irritable bowel leads to an irritable brain. So before we dive any deeper, let’s define the features of this gut brain axis. The gut, which basically we talked about is the GI tract. It starts at your mouth and it goes to your anus. It includes esophagus, stomach, small intestine, large intestine, all the way down to the bottom. The vagus nerve is the longest nerve that comes from your brain called the cranial nerve. It travels through the brainstem to the gut and it connects the gut to the central nervous system, and it goes through the entire GI tract. Think about it, you’ve got huge amounts of gut. If you laid out your small intestine flat, it would be the surface area of a tennis court, and then there’s your large intestine and then your esophagus. So all that is really important.
The vagus nerve connects to other things like your heart and lungs and so forth, but this vagus nerve is a really important part of your nervous system called the parasympathetic nervous system. This is the relaxation nervous system. It also is called the autonomic nervous system or automatic nervous system. So it’s not usually under our willful control, although we can regulate it through various practices. The yogis have been doing this for centuries. It regulates involuntary sensory and motor functions. You say, I’m going to move my arm. So you move your arm, but you’ll go, oh, I want to digest my food. Can you please digest the food in there? Can you please regulate my heart rate? Can you control my blood pressure? You don’t really think about it. These things happen automatically. A lot of this happens through this automatic system. There’s a lot of signaling that happens through this nervous system.
For example, it helps control appetite. And how does it do that? Through peptide hormone called GLP one, right? You might’ve heard about this. This is ozempic wegovy and so forth. These are drugs. Now, quote drugs, but they’re not really drugs. They’re just mimicking your body’s own GLP one at a much higher concentration. This is also known as the satiety hormone. It makes you feel full, which is why people don’t eat because they take this shot and they don’t feel full. And this is also why people lose weight. They take this shot, they feel full, they don’t want to eat as much and they lose weight. This is typically secreted in the lower part of the intestine, but it basically reduces your appetite and promotes satiety, and it says a single via the vagus nerve. So this is really important, this drug, right? It’s ozempic. So this is something your body makes.
Also, there’s other hormones that are regulated called CCK or Cholecystokinin peptide YY, really important and other compounds called short chain fatty acids. We’re going to talk about why they’re important, but these are made by your gut that suppress appetite, by making you feel full, by activating the vagus nerve. And these are things that you can regulate. Leptin is another hormone produced and fat cells and in the gut, and it’s also the feel full hormone. There’s many of these redundant pathways in your body and it exerts its effects through the vagus nerve. This network, this gut brain, this second brain or enteric nervous system, is a vast network of, like I said, almost 500 million neurons. That’s embedded in the lining of the GI tract. What’s in them not only is nerve cells, but also hormonal cells, right? Enteroendocrine cells, and they’re throughout the entire GI tract and they’re involved in sensing all sorts of signals, right?
What nutrients you’re taking in taste, mechanical stimuli, fiber, they detect the microbes. What’s going on in there? They help sense toxic compounds. So it’s really a critical system and as I mentioned, this is called the second brain. It operates independently, but also with the brain. Brain, right? The central nervous system by the vagus nerve, and it controls everything, right? Got motility, right? Whether you’re constipated or have diarrhea, enzyme secretion, digesting your food hormone release that regulates appetite, and then mention the full hormones or the hungry hormones like ghrelin, and it also affects blood flow that aids in digestion and absorbing nutrients. So it’s super important. Now, the microbiome consists of about a hundred trillion microbes, maybe about 5,000 different species, and you got about two pounds of poop in there of microbes in your GI tract. So what do these microbes do? Well, they help you digest your food.
They produce vitamins, they regulate hormones, and they help you get rid of toxins. It interacts with your whole enteric nervous system and central nervous system. So the microbiome is a whole nother thing that’s involved, right? You don’t just have your brain, brain and your second brain. You have your microbiome brain, let’s call it, right? It’s really important and it helps regulate everything in your body and it regulates mood, particularly a lot the composition of your gut microbiome. And I’m going into this because it’s important to understand. If you’re going to understand what to do about fixing your gut and how this all works, I want you to understand the importance of understanding your gut as it regulates to regulating your mood and brain health and pretty much everything else. So the composition of your gut flora, it varies from person to person. It depends on their diet.
So if you’re a hunter gatherer and eating meat or bison all the time, or if you’re a vegan, all that changes based on what you’re eating. It changes based on your lifestyle. Stress, toxins, genetics all regulate the microbiome. Now, there’s a large research project going on called the Human Microbiome Project. It helps map out the gut microbiome of individuals who are healthy and who are sick to understand better their gut bacteria species. So what defines a healthy gut? What defines a sick gut and how does that relate to different diseases? Now, what’s amazing also to me, this blew my mind when I learned about it, is it a third to a half of all the metabolites in your blood, all the thousands of molecules floating around in your blood that regulate everything in your body are not human. They’re from your gut microbiome. In other words, these molecules produce from bacteria in the gut are absorbed and that impact your whole biology, including your brain and your mood.
There’s still a lot we don’t know about what makes a healthy gut or a sick gut, but we know a lot. Now, your gut microbiome can produce healing metabolites that keep your gut and immune system healthy. Things like short chain fatty acids, we’ll talk about those soon vitamins like B12, for example. Riboflavin made in your gut enzymes, or it can produce harmful metabolites. So bad bugs produce bad stuff, good bugs produce good stuff, and the bad metabolites from bad bugs can be things like cytokines. We’ve learned about from covid, the cytokine storm. These are inflammatory messenger molecules of your immune system, endotoxins, literally poisons. We call these lipopolysaccharides. These are endotoxins things that are toxic produced by bacteria that can be absorbed across a leaky gut cause you to be inflamed and create disease including obesity, mental health issues, and much more. So bad bugs make you inflamed.
And almost all issues related to mental health, this is really important to understand almost all mental health issues and brain issues, whether it’s Parkinson’s, Alzheimer’s, autism, a d, D, depression, anxiety by PO disease, schizophrenia are all caused by inflammation in the brain. So if we fix the inflammation, we can fix many of these things and we’ll talk about how to do that soon. Now, what is this gut mood connection? We talked about what is the gut and what is the gut brain and the second brain and the first brain and the hormones, okay, we talked about all that. The gut microbiome actually influences brain health and function, and it impacts your mood, impacts your stress level. Literally, you could have stress molecules produced in your gut that are not because of something happening outside, but something happening inside, and it increases risk of depression, mental illness via a complex network of things, nerve cells, endocrine cells or hormone cells, immune pathways.
It’s the psycho neuroendocrine immune system, right? We talked about this a lot. It involves all sorts of activities like the transport of neurotransmitters, metabolites, cytokines, and certain species of gut bacteria are directly involved in the production of neurotransmitters affecting both the gut and the brain. Let’s talk about some of them. So dopamine, for example, is best known for its role in reward pathways ledge motivation. For example, we know about Adderall or these a DD drugs. They all stimulate dopamine. Sugar does all the addictive compounds. We like to so did altruism by the way. By way. There are certain bacteria that help embrace dopamine. Things like lactobacillus, plantar bacillus, subtles, bacillus serious, and certain strains of e coli that are beneficial. Pretty cool. What about serotonin? Another important neurotransmitter involved in mood. It’s involved in regulating various physiological processes including the secretions of your intestinal tract, peristalsis, motility, respiration, blood vessel regulation, behavior, mood.
We know all about Prozac. That’s how it works through inhibiting serotonin reuptake in the nerve cells in the brain, which makes you have more serotonin. Now, certain bacteria that are good can actually help improve the concentration of serotonin. And by the way, 90 to 95% of serotonin in the body is produced in the gut, but bacteria like lactobacillus, plantar or streptococcus, which are healthy bacteria, you can get through supplements or you can help grow the diet, actually help with improving serotonin. What about gaba? This is the relaxation neurotransmitter. It’s sort of the receptor upon which Valium and the benzos work. So GABA is sort of a relaxation neurotransmitter and it helps reduce neuronal excitability helps reduce anxiety and stress with sleep, and a lot of bacteria can help produce this in your gut like bifidobacterium, lact, asil, plantarium, lactide, lact prognosis, even things like Akkermansia.
We talked about the silhouette colline from pendulum therapeutics. She basically was growing akkermansia in this big vat to be a probiotic, and they started to analyze what was in what were the metabolites that the Akkermansia was producing, and they actually found a big spike and it turned out to be gaba. So this akkermansia bacteria, which is so important for so many reasons and can have many podcasts and things we’ve written about it, I’ll shared in the show notes. Akkermansia actually produces gaba, so it’s like a natural Valium. Other bacteria can influence the levels of neurotransmitters by encoding genes for enzymes that produce neurotransmitters or directly impacting the synthesis of neurotransmitters or the breakdown of neurotransmitters. So the microbiome plays a huge role in all sorts of neurotransmitter function. For example, the conversion of neurotransmitter precursors like tryptophan, you get from your diet into serotonin, which is the happy mood chemical.
They’re also involved in the production of a really important compound in the body called BDNF. BDNF means brain derived neurotrophic factor. This is like miracle growth for your brain cells increases neuroplasticity, neurogenesis meaning the making of new brain cells and the connections between brain cells. Also, bacteria can produce really important compound called short chain fatty acids. These are called postbiotics. A lot of these things are postbiotics, right? Prebiotics, fertilized good bacteria. Probiotics are the bacteria and postbiotics are the compounds produced by the bacteria that are bioactive molecules or metabolites that are produced by healthy gut bacteria and impact our bodies and brains. Now, short chain fatty acids are one of the most important of these. Why? Because they affect every level of our health regulating cancer, metabolism, inflammation, and gut health, but they also cross the blood brain barrier and they affect brain health by regulating neurotransmitter levels and they reduce inflammation, which again is at the root of all this mental health stuff.
There’s a lower abundance of short chain fatty acids producing bacteria and bacterial diversity. I’m not making this stuff up. Studies show this very clearly. For example, in people who have depression anxiety, there’s a lower amount of the bacteria that produce these short chain fatty acids. So the importance of microbial diversity for gut health, for mood and mental health cannot be overstated. A higher diversity complexity of your microbiome, it’s associated with healthy aging, better immune function, better detoxification, metabolism, weight, everything, and a stronger gut barrier, which is really important to prevent basically what’s in your gut. A sewer meaning poop and food particles from leaking in cross the barrier entering your bloodstream, triggering an immune response, triggering inflammation and all the diseases of our chronic disease society, right? Not just mental health issues are linked to inflammation, but heart disease, cancer, diabetes, dementia, obesity, all these are inflammatory disease, not dementia, obviously, autoimmune disease and allergic disorders, all of which are connected to leaky gut and inflammation.
If you have high microbial diversity, meaning a large amount of species, think about it as like a rainforest as opposed to a mono cropp, right? You want a rainforest in your gut, not a mono cropp of bugs, right? The higher diversity leads to good things like more short chain fatty acids, things like butyrate, aate, these short chain fatty acids feed the intestinal cells aligning. They strengthen them and they prevent lots of issues. They’re also very anti-inflammatory, and as I mentioned, they cross the blood-brain barrier, reducing inflammation in the brain. Think about that. Your gut microbiome reduce metabolites. They get absorbed, they go through your bloodstream, go through the brain and reduce inflammation. It can improve not only your physical health but your mental health. It’s kind of mind blowing actually. Now, stress also is a bad thing for your microbiome. It doesn’t like stress when you have a lot of stress.
It reduces microbial diversity by increasing stress. Hormones like cortisol increases, inflammation affects gut motil so you can get diarrhea or constipation. It can change your eating habits by making you crave more sugar and carbs, and that affects your microbiome. So it’s a vicious cycle. A mouse study found that it only took two hours of exposure to a social stressor to change the microbiomes relative abundance and profile. Think about that. Two hours of stress in a mouse screws up their microbiome, and this is a human study, so you should listen up on this one. In couples showed that if you have marital distress and more hostile interactions with your partner, it can lead to higher amounts of leaky gut and also when you had this marital distress, it leads to mood issues and that leads to higher levels of something called lipopolysaccharides, which are these toxic endotoxins that create inflammation in the body that come from bad bugs, and those treat inflammation.
That was amazing to find in this couple study that actually looked at bad relationships and found that those who had bad relationships essentially in bad communication and more marital stress had more of these bad bugs in their gut. They produced more of these, polysaccharides had more inflammation, and that leads to more health issues and mental health issues. That’s not good. So time to get your relationship straight. That’s a whole nother topic, but we’ve had some podcasts on that too. Now, before I get into what to do about this and how to fix your gut, which I’m getting to, I promise, so stick with me. I’m going to talk about a little bit more about how gut dysbiosis affects our mental health. The first is too many bad books, right? Bad bacteria, parasites, yeast, and not enough good bacteria are driving the problem. So good bacteria, lacto, basil, akkermansia, bifidobacterium, and many more.
That leads to what we call dysbiosis, this imbalance in the bacteria in your gut. So these bad bugs release, as I mentioned, endotoxins, these LPSs that induces intestinal inflammation, it causes a leaky gut. It weakens the connections of called the tight junctions between the cells in your gut. That creates a gap and allows food particles and bacteria to leak in, and that’s a real problem because then you get leaky gut and that creates more of a vicious cycle. Another thing that can be triggered by high levels of gluten in the diet is something called zonulin. Zonulin is a molecule that is produced in response to certain infections like cholera, which is how it’s discovered. Alessio Fasano discovered this. He is the world’s expert on celiac, and you can listen to my podcast with him, which ideas ago, but are still relevant and great, but xin is triggered by an increase in gluten in her diet, and it modulates the permeability of your gut, so it looses the tight junctions, meaning the little Lego things that hold your cells together and allows the gut to become leaky.
Now, Alessio Fasano and 2000 discovered this and his team at the University of Maryland School of Medicine, and this is what happens during acute celiac disease. Now, leaky gut causes systemic inflammation, and when you have this, it’s linked to autoimmune disease. Things like type one diabetes, ms inflammatory bowel disease, lupus, Hashimoto’s, and lots more. It also causes metabolic issues, poor metabolic health like diabetes, obesity, and of course mental illness. One of the first things I do when someone has a mental health issue is I check their full celiac panel. I even do extra antigen testing of over 20 different antigens that come from weed and gluten, and I get rid of it if I see anything cooking in there. There’s a huge link between autoimmunity too and mental health issues. This is really important because inflammation from any source will drive mental health issues, and a 2023 study showed that over half of the people with an autoimmune disease also have depression anxiety.
Now, it could be because they’re sick, but it could be also because they have inflammation. Stress leads to leaky gut as we talked about. Oh, another interesting thing we know in medicine is this drug we use. It’s called interferon. Interferon is a drug we used to treat certain immune disorders including ms, and this drug causes depression. Why? Because it increases inflammation. So we know that you can induce depression by taking a drug that caused inflammation. The link is really clear here. Now in humans who were given the bacterial toxin, lipo polysaccharides, right? Intravenously, which sounds terrible, but they were basically given as an experiment, toxins that come from bad bugs in the gut when they were given these intravenously. Now, what happened when they did that, it triggered a whole cascade of inflammatory cytokines, IL six, TNF, alpha L 10, doesn’t really matter the name, but basically these inflammatory cytokines increased two to three hours after the administration.
Now, what was interesting was that these higher levels of IL six could produce a huge anxiety response, so higher levels of these circulating cytokines also were found to be linked with major depression, anxiety, and then much more. So really important to get your gut healthy if you want to be mentally healthy. The link between bad bugs or dysbiosis and mental health is clear, right? There’s no lack of data. Now on this, when I started doing this 30 years ago, there was data, but you had to dig for it, and certainly it wasn’t in zeitgeist and there weren’t departments in major academic medical centers looking at this, but now there are now systematic review and meta-analysis looking at biomarkers of gut dysbiosis in severe mental illness and chronic fatigue showed that zonulin meaning from gluten triggered gluten, which caused leaky gut and LPS, these bacterial toxins were higher in people who had these problems, right?
Mental health issues and chronic fatigue than in controls. The paper found an association with reduced microbial diversity and lots of mental health issues from depression to anxiety, bipolar disease, schizophrenia, and of course chronic critique. In another study, they mentioned surrogate markers of bacterial translocation, which means they were able to look at markers of bacteria that had gone across a leaky gut, and they showed that these markers of basically bad bugs getting across a leaky gut and their metabolites found these things are elevated by threefold in schizophrenics. That’s 300%, and they significantly correlate with inflammation. And we also see dramatic changes in the microbiome, not just in mental health issues like depression, anxiety, but in kids with autism, it’s well known that these kids have horrible microbiomes. Okay, so bad news. That was a lot of bad news, a lot of interesting science. What the heck do you do?
What’s a functional medicine approach to getting to the root cause of dysbiosis? You have to get rid of the bad stuff, right? Really functional medicine’s pretty damn simple in the execution. It’s pretty simple. Get rid of the bad stuff, put in the good stuff, your body knows what to do. It’s the science of creating health. So what’s the root cause of gut dysbiosis? It’s our inflammatory sad diet or standard American diet. It’s ultra processed foods that are low on prebiotic fibers. They’re low on probiotic rich foods, low on polyphenols, colorful compounds that help fertilize good bacteria, and they’re high in things that cause really bad bugs to grow like sugars, refined flowers, inflammatory fats, various chemicals in our food preservatives and food additives lead to significant dysbiosis, and we have a link here to all the research on this. Again, I’m not making this stuff up.
All the data is there. All the things I’m saying are backed by peer review research. So have a look if you’re interested. Also, higher intake of these foods were associated with a lot of other things like inflammatory bowel disease, so things like emulsifiers, gums, preservatives, flavorings, disrupt, they got microbiome. They cause a leaky gut that drives inflammation and that drives mood disorders, and obviously all these other chronic diseases, the ratio of good bugs to bad bugs goes down when you have ultra processed food. It’s also been linked to low levels of short chain fatty acids, which we talked about, which are so important. High sugar diet in mice, just two days, right? High sugar diet. And by the way, we eat about 152 pounds of sugar and 133 pounds of flour per person per year in America. So in two days of just a high sugar diet in mice, it caused a dramatically lower level of short chain fatty acids and increased the leaky gut, and it decreased the diversity of your microbiome, all bad things that create disease, inflammation, and mental health issues.
When your gut’s impaired in that you have a bad microbiome, it disregulates the feeding signals. So the brain via the vagus nerve and the gut brain axis, meaning the normal communication that helps you feel full and regulates your appetite and makes you not overeat, are all screwed up by a bad microbiome. What does it do? It lowers GLP one. Wow. This is the ozempic drug. So basically eating ultra processed diet lowers GLP one, which you want to have high to control your appetite so you can change your GLP one levels that your body makes simply by optimizing your diet. As I’m talking about. Also, it decreases a really important hormone called P-Y-Y-P-Y-Y is the break on your appetite that’s produced in the lower part of the intestine. Ultra processed food increases ghrelin, which is the hunger hormone, and it makes you hungry and crave more junk food.
Also, the endocrine cells in our gut or the enter endocrine cells, they play a really important role in sugar cravings, and they stimulate the vagus nerve to transmit signals to the brain who want more sugar. So the more sugar you eat, the more crap you eat, the more you want. And of course you all this because you’ve experienced it, the science is there to show it. Also, different things can damage the gut. You might want to get rid of and try, and I’ve read a book about this called The 10 Day Detox Diet, which you can do for more than 10 days, obviously, but it geared all the bad stuff, puts in all the good stuff, and then you get to see how you feel. And I’ve seen dramatic change literally in days three to five days. People have dramatic change in their mental health by simply changing their diet and things like gluten, dairy, other food triggers that are not necessarily allergies that are just inflammatory.
Things like sugar, dairy, soy, gluten, MSG, very much bad for the brain. It’s called the cytotoxin. Other things can also affect your microbiome. You want to get rid of stress. Also, lack of sleep. We talked about sleep plays a big role in your microbiome. Certain drugs that we take all the time, gut busting drugs, we want to minimize or get rid of, like anti-inflammatory drugs like Advil, antibiotics, and also acid blocking drugs like Prevacid or Prilosec, the purple pill. These have a lot of bad effects on the gut, and you want to really reduce these because they have really a negative impact on your overall gut microbiome. Steroids also important to reduce, and the intake of those reduce your exposure to toxins, which do affect the gut, like mercury and mold. Also bad chemicals. So just reducing your exposures overall. I’ve done a lot of podcasts on this, but go to ewg.org and you can learn a lot about how to reduce your exposure to environmental toxins.
If there’s pathogens there, you want to get rid of ’em, like bad bugs, parasites, bacterial overgrowth. Remember those stories I told at the beginning about the girl with all that crazy behavior and the lady with OCD. Again, this was just by getting rid of these bad bugs and then you got to help improve the quality of the overall gut health. So I use stool testing. It’s been a part of my practice for 30 years. I use Genova Diagnostics, GI effects tests, really the best test out there. I think for looking at your gut microbiome and all the associated functions of it. You need to go to a functional medicine doctor to get that, but it’s really an important way to look at what’s going on. So what’s the functional medicine approach to healing? Well, we talked about the five R program. Basically get rid of the bad stuff, putting the good stuff first is remove the bad stuff.
Place the things that are missing like enzymes, repair the gut lining and reintroduce or inoculate with probiotics and restore your gut nervous system by reducing stress. So it’s a five step program that works really well, and it’s not that hard to implement, and it can be very powerful. So what’s the first step? Remove the bad stuff. Remove common food triggers, gluten, dairy, corn, soy, potentially eggs for some people, ultra processed food, refine carbs, sugar, alcohol. Get rid of the bad bugs, right? If you have overgrowth of bugs like mal bowel overgrowth or yeast or parasites, you need to get rid of ’em. Do an elimination diet, get rid of potential food sensitivities. You do the 10 day detox diet. We’ll put a link to it here in the show notes. Do it for at least four to six weeks, and then slowly reintroduce things to see how you’re doing and what triggers you.
So might go, oh gee, I got rid of all this food and I add back corn and it really reacts. Or I have eggs that add back, and that really triggers something. Or it’s gluten. So you’ll learn from your body. Don’t listen to the doctor. Listen to your body. Your body’s the smartest doctor in the room. I bet you want to replace what’s missing. Sometimes people need digestive enzymes or hydrochloric acid. They might need the right nutrients to help fill nutrient gaps. They also will need prebiotic foods and prebiotic fibers. And 95% of Americans aren’t getting enough fiber. They’re undereating plant foods, and that affects the diversity of beneficial bacteria species because these plant foods contain in polyphenol. So these are all food for the healthy bacteria. We want to replace those in our diet. We also want to repair the gut lining. This is done through taking a bunch of things that really improve the overall health of gut, and it’s using food as medicine.
So it’s eating whole foods, minimally processed foods, lots of probiotic foods, polyphenols from colorful foods, prebiotic fibers from a diversity of colorful plant foods, vegetables, fruit, not seeds, certain beans, whole grains, all really important in helping create a healthy microbiome. An observational study using the UK Biobank data found that high intake of fruits and veggies and fiber was positively associated with mental health in a population of over 500,000 middle aged adults. So if you ate healthy food, you were less likely to have issues with mood. Big surprise, right? In a randomized controlled trial, this is a higher standard of research. Our researchers looked at the influence of psychobiotic diet. Now, I love this term, psychobiotics. You’ve probably heard of probiotics, but what’s a psychobiotic? It’s probiotics that affect your mental health. It’s a diet that grows the right bugs, that produce the right psychobiotics, right, the right psychobiotics that influence your mental health.
And when they had a diet that they called a psychobiotic diet, they looked at its influence on the microbe profile in your gut, on the function of your microbes, as well as mental health outcomes in 45 healthy humans for four weeks. Now, they did dietary intervention. Basically, they called the psychobiotic diet and they found a 32% reduction in a perceived stress. Now, the diet included fruits and veggies, high in prebiotic fibers, about six to eight servings a day. Things like onions, lees cabbage, apples, bananas, oats grains, five day servings, a day, beans, three to four servings a day, fermented foods, right, like sauerkraut, keur, kimchi, kombucha, yogurt, et cetera, two to three servings a day, and bone broth, which also contains glutamine. Lots of really helpful things you can do to repair your gut. You also want to inoculate, put in probiotics to reintroduce healthy bacteria to your ecosystem, and a big systematic review of randomized controlled trials, probiotics.
And again, these are a review of all the studies that were done in the highest quality of evidence, randomized controlled trials. They found probiotics significantly reduced depression and depression scores and major depressive disorder in populations under 60. And these are certain bacteria that made a difference like bifidobacterium, breve, longum, lack of cel hypnosis, ados. I mean, think about it, when you go to the psychiatrist, they don’t recommend probiotics, but they recommend antidepressants. They should recommend probiotics. Also, you can eat probiotic rich foods in a randomized double-blind placebo controlled trial. Again, the highest level of evidence consuming a hundred grams a day of probiotic yogurt or a multi-species probiotic capsule, right? So you can take probiotic yogurt. That spike or a probiotic pill for six weeks had a significant improvement in depression, anxiety, and the stress scale of petrochemical workers. That’s amazing, right? So we not only have sort of this theoretical idea of how this works, but we have randomized controlled trials in humans showing this works.
Also, you want to restore this makes your lifestyle manage stress because that plays a big role. Exercise, get outside in nature, sleep well, stay hydrated, all the obvious things. So we know that the gut plays a huge role in our mental health and in every aspect of our health, but today we focus on mental health. So there’s much you can do to reset your gut, to treat your brain, and it’s really important. Now, as we wrap up today’s conversation on the profound impact of our gut microbiome mental health, it’s really clear that nurturing our inner garden holds the key not only to our physical wellbeing, but to our mental and emotional resilience as well. So by embracing the principles of functional medicine, we can help grow flourishing microbiome. We can foster a balanced gut brain axis and it’s fundamental to our overall health. Make sure you take care of your gut if you want to take care of the rest of your health, and it’ll help your mood, your brain, and everything else. Thanks for
Speaker 2:
Listening today. If you love this podcast, please share it with your friends and family. Leave a comment on your own best practices on how you upgrade your health and
Speaker 3:
Subscribe wherever you get your podcasts.
Speaker 2:
And follow me on all social media channels at Dr. Mark Hyman, and we’ll see you next time on The
Speaker 3:
Doctor’s Farmacy. I’m always getting questions about my favorite books, podcasts, gadgets, supplements,
Speaker 4:
Recipes, and lots more. And now you can have access to all of this information by signing up for my free Marks Picks [email protected] slash marks picks.
Speaker 3:
I promise I’ll only email you once a
Speaker 4:
Week on Fridays, and I’ll never share your email address or send you anything else besides my recommendations. These are the things that have helped me on my health journey, and I hope they’ll help you too. Again, that’s dr hyman.com/marks picks. Thank you again, and we’ll see you next time on The Doctor’s Farmacy.
Speaker 3:
This podcast is separate from my clinical practice at the Ultra Wellness Center and my work at Cleveland Clinic and Function Health, where I’m the Chief Medical Officer. This podcast represents my opinions and my guest opinions, and neither myself nor the podcast endorse the views or statements of my guests. This podcast is for educational purposes only. This podcast is not as substitute for professional care by a doctor or other qualified medical professional. This podcast is provided on the understanding that it does not constitute medical or other professional advice or services. Now, if you’re looking for your help in your journey, seek out a qualified medical practitioner. You can come see us at the Ultra Wellness Center in Lennox, Massachusetts. Just go to ultra wellness center.com. If you’re looking for a functional medicine practitioner near you, you can visit ifm.org and search, find a practitioner database. It’s important that you have someone in your corner who is trained, who is a licensed healthcare practitioner, and can help you make changes, especially when it comes to your health. Keeping this podcast free is part of my mission to bring practical ways of improving health to the general public, and keeping with that theme, I’d like to express gratitude to the sponsors that made today’s podcast possible.

Want to read the full transcript for free?
Enter your name and email to sign up for our newsletter and unlock the transcript
Invalid email address

If you are looking for personalized medical support, we highly recommend contacting Dr. Hyman’s UltraWellness Center in Lenox, Massachusetts today.

Send this to a friend