The Brain-Gut Connection with Dr. Emeran Mayer

EMERAN: We've all experienced a connection between our brain and our gut.

If you ever felt butterflies in your stomach or based a major life decision on a gut feeling, you have experienced the brain-gut connection.

This connection has been recognized by ancient healing traditions for centuries.

Now, modern science is revealing that this vital connection between your gut and your brain impacts everything.

Your physical health, your mental health, even the choices you make.

When the brain- gut connection is out of balance major health issues can crop up.

Of course, that includes gut ailments like irritable bowel syndrome, allergies and food sensitivities.

But new science is revealing that the health of your gut also affects your brain.

ANNOUNCER: An award-winning gastroenterologist and neuroscientist, Dr. Emeran Mayer has studied brain-body interactions for the last 40 years and is considered a pioneer and world leader of medical research into brain-gut interactions.

EMERAN: To protect your brain, you need to take care of your gut.

With a few simple lifestyle changes, you can help protect your brain from serious diseases like Parkinson's, Alzheimer's and cognitive decline.

You can ease digestive symptoms.

You can enjoy a happier mindset and better mental health.

This is The Brain- Gut Connection.

I'm Dr. Emeran Mayer.

I was born in a small town in Bavaria, where my family has run a confectionary business since 1873.

It was clear to everybody in the family that I would be the sixth generation to take over the business.

I had to make an agonizing decision.

Should I do what was expected?

Or should I pursue my passion for science and healing?

As a young man, I went with my gut and decided to become a doctor.

It was my first big gut-based decision.

After medical school, I did my clinical training in North America and became a gastroenterologist, neuroscientist, and professor at UCLA.

I've dedicated my career to studying the connection between the gut and the brain, between mind and body.

Nothing occurs in isolation.

What's happening in your gut is affecting your entire body, your immune system, your brain, your emotions, and the way you make those gut decisions.

In this program we'll meet some of the leaders in microbiome science.

We'll take a revolutionary new look at the connection between your brain and the trillions of microorganisms living in your gut.

We'll discover a new understanding of emotions, decision-making, mental health and chronic disease.

Plus, we'll learn simple lifestyle solutions to improve your brain health by targeting the gut microbiome.

The connection between the body and the mind has been ignored by western medicine for hundreds of years.

But finally, modern science is beginning to understand this two-way communication between our gut and our brain.

It's a fascinating story and one that is still unfolding.

This new science is guiding us on a path back to ancient wisdoms of interconnectedness, teaching us the importance of taking care of body and mind.

This connection between the gut and the brain has been rediscovered through microbiome science.

Microbiome science is transforming the way we look at gut health, brain health, and the prevention and treatment of our most common chronic diseases.

So what is the microbiome?

ELAINE: The gut microbiome is a vast and diverse community of microorganisms, including bacteria, fungi, viruses, all sorts of single- celled organisms that live in the GI tract.

EMERAN: When it comes to the microbiome, most people think about digestive health, but the trillions of microorganisms that live in your gut play an essential role throughout your entire body, including your metabolism, your heart, and perhaps most importantly, your brain.

On the other side of this two-way street, your thoughts and emotions also influence what's going on in the gut.

In other words, what's happening in your brain is impacting your gut, potentially causing digestive symptoms.

The brain-gut connection impacts your entire body and understanding it will make a real difference in your physical and mental health.

We used to think of all bacteria as being dangerous or unhealthy, but the 40 trillion microbial organisms living in your gut are active participants in the communication between your gut and your brain.

DREW: In medicine for so long, we've just, you know, we've been very proud.

We can kill a lot of bacteria, kill all the bacteria, like that's- we're good at that.

So now I think it's a little confusing sometimes to patients like, I want you to drink the bacteria.

Don't kill the bacteria, drink the bacteria, and that we're having individuals eat and drink live bacteria, live fermented foods because of the microbiome.

EMERAN: Our gut microbes actually talk to our brain and our brain communicates back to them.

For example, what happens when you're stressed or preoccupied with negative emotions?

ELAINE: Stress, I think, is one of the environmental factors that has been reproducibly shown to influence the composition of the microbiome.

EMERAN: Imagine you're driving in traffic and another car cuts you off, your jaw clenches, your brow furrows.

From the passenger seat your spouse can see the angry expression on your face.

Your emotions are so apparent to people around you because your brain sends signals to your face's many small muscles.

Every emotion has a corresponding facial expression that we can see.

What you can't see is how your emotions affect your gut.

When you are angry, your brain sends signals to your digestive system, just like it does to your facial muscles, and your digestive system responds dramatically.

Your stomach goes into vigorous contractions feeling as if it's tied up in knots.

It increases the production of acid and slows digestion.

Similarly, a distinct pattern happens when you feel anxious or worried, and when you're depressed digestion nearly grinds to a halt.

We know instinctively that our brain and gut are connected, and now the science is beginning to prove it.

There's a constant vital stream of information going from the gut microbes to the brain.

This informs the brain about the health of the gut, our diet and the activity of the immune system.

ELAINE: I think that there is just continuous interplay between the microbiome and our own biology, and especially with the nervous system, which is really dedicated to allowing us to interface with the external world.

Like our whole sensory systems of the- of the nervous system.

So I think there's definitely a continuous interplay given that gut microbes are really part of us in- internally, but also intersecting between us and the environment.

EMERAN: We know that the trillions of microbial organisms inside our gut cause dramatic changes across our whole body, and we now know that these microbes communicate with our most sophisticated organ, the brain.

When this communication system between your gut and your brain is out of balance, we can start to experience serious health problems, digestive disorders, obesity, allergies, and food sensitivities, even heart disease and some cancers.

We can also experience mental health difficulties like anxiety, depression, and cognitive decline.

So what's throwing our microbiome off balance causing all of these physical and mental health problems?

The answer, our modern lifestyle.

Poor diet, lack of movement, consuming antibiotic medicines, or even eating meat that was treated with antibiotics.

These things have all disrupted what's happening in our gut, and therefore, your brain.

MARTIN: 76 out of a hundred Americans have gotten a course of antibiotics in the last year, and this has been going on year after year.

The average child has gotten 10 courses of antibiotics by the time they're 10, about 20 courses by the time they're 20.

And again, we're just- every year we're getting so many antibiotics.

I think we're continuing to damage the microbiome.

EMERAN: But antibiotics aren't the whole story.

Other surprising gut- disrupting factors include chronic stress, loneliness, and poor sleep.

These modern challenges are all disturbing this ancient connection between our gut and our brain.

And it's creating a modern epidemic of chronic diseases.

My patients often ask me, "What is a healthy microbiome?"

"How do I know if my microbiome is healthy?"

and, "What can I do to improve my gut health?"

ERIKA: It probably depends on how you're defining healthy.

So a microbiome that would be beneficial for longevity might be different than a microbiome that benefits reproductive success or a microbiome that resists chronic disease.

MARTIN: What is a healthy microbiome?

That's- that's probably the most difficult question because microbiomes are so varied between people, but I think we can say that a microbiome that's very diverse, that has a certain kind of balance, we're learning about that balance, and a microbiome that's not full of certain microbes that we recognize as being costly to us humans like the e-coli and its- and its cousins.

These are bacteria that- that often show up in disease and- and we think they're kind of a marker for an unhealthy microbiome.

EMERAN: Science is still working to determine what makes a microbiome healthy.

However, we're beginning to understand what causes an unhealthy microbiome.

Mainly the stresses of our modern lifestyle.

ERIKA: Let's say you could somehow figure out what an ideal microbiome was, and you could give that to a child and nurture that over a period of time.

As soon as that person changes their lifestyle, that microbiome will adjust to that change in lifestyle.

I mean, the microbiome is an aspect of our biology that's just highly sensitive to our- to our environment.

So it will change and adapt.

And if you adopt unhealthy lifestyle, you know, consuming a lot of processed, packaged food, not eating a lot of fruits, vegetables, all these things that we know are healthy, your microbiome will change and it- it may not matter what the microbiome you had five years ago.

It will, you know, it could potentially drive these diseases.

So that being said, I think we're starting to have a pretty good idea of what an unhealthy microbiome looks like.

There are, you know, very specific things.

Low diversity microbiomes in general are never a good thing.

Those are associated with all kinds of diseases.

ELAINE: There are many kind of things that can shape the microbiome during adulthood.

So a lot of environmental factors like diet is a major determinant of what the microbiome looks like.

But even things like our exposure to different medications can influence the microbiome.

I think in the short term.

A lot of the choices that we make during adulthood, in terms of our lifestyle can influence the composition and function of the microbiome.

EMERAN: The microbes in your gut learn, respond and change based on your environment.

Unfortunately, our modern environment and diet has become less gut friendly.

One fascinating study demonstrating how moving to a modern western society can quickly disrupt a person's health.

ERIKA: There was another study that was done looking at a group of immigrants from, Hmong immigrants into the United States, into Minnesota, and they could watch their microbiome in a span of just months change as they started adopting the American lifestyle.

Our human genome, of course, takes a lot longer to adapt to changes in environment.

That doesn't happen even within one or two generations.

I mean, that can take thousands of years.

And so there is this potential that as our environment has changed so rapidly, you think about the advent of antibiotics, the advent of processed foods, and, you know, this move away from more agricultural lifestyle to an urban lifestyle where we're not being exposed to microbes or animals as much as we used to.

The microbiome adapts to that very, very quickly.

So you could potentially have a microbiome that's well adapted to city urban, sort of American junk food, high antibiotic lifestyle, but then your genome still is in that mindset of, you know, gathering food and not having a lot of antibiotics all the time and- and, you know, those aspects of our life that- that used to be such a hallmark of human existence for thousands and thousands of years.

And so if our human genome is expecting a certain microbiome, and now that microbiome has changed so quickly, maybe these two don't- don't play nice together anymore.

They don't interact well together, and that could be potentially one of the reasons why we see increases in these chronic diseases that are just becoming more- not only more and more common, but are being diagnosed in younger and younger individuals.

So- so this mismatch doesn't appear to be getting better.

If anything, it seems to be getting worse.

EMERAN: Lifestyle factors like poor diet certainly have an immense impact on the health of your gut.

But remember, just like your face, your gut mirrors every emotion that arises in your brain.

That means the state of your mental health including chronic stress, worry and depression, can also have a major impact on your gut health just like poor diet.

This is not a problem if it is a short-lived emotion.

TRACY: You know, we think of stress as a bad thing, but we experience as human beings stress every day, right?

When your- when your body perceives that you're hungry and during the day, that's a stressor to the body, right?

There's tons of responses that the brain receives information from the body about changes, but if it's enough chronic, it begins to tell your body that this is an event it needs to respond to in a different way.

STEVE: In fact, this is the- the sort of the recipe for the, you know the- the plague of chronic disease that afflict us in- in, you know, sort of advanced industrialized economies and in social ecosystems more general.

They don't leave people feeling securely integrated in a warm, supportive community.

They leave people feeling, you know, very much threatened by competition and insecurity, and this is tremendously economic productive if people are, you know, feeling insecure, they work harder, right?

They- they don't wanna, you know, sort of suffer from- from disadvantage, but curse in- in a physiological sense.

It just keeps all this low-grade stress biology running and that low-grade stress biology biases, the way our bodies work in ways that, you know, really were not characteristic of, you know, our- our ancestral social conditions and essentially leave our body working in ways that it wasn't meant to run.

EMERAN: When negative emotions become chronic, these emotions don't just stay in the brain.

They will interfere with the health of your gut and therefore your entire body.

Whether it's affected by stress, poor diet, or other lifestyle factors, this disruption of the brain-gut connection has resulted in an epidemic of chronic diseases like heart disease, non-alcoholic liver disease and type 2 diabetes to mention just a few.

The good news is that you can rebalance your breakout connection by making simple changes to your own environment.

Coming up, a revolutionary new look at how the mind and gut communicate with each other and the role this plays in maintaining the health of your body and your brain.

We'll learn how gut health and the microbiome influence your mood, decision making and mental health.

And we'll reveal simple solutions to improve the health of your body and brain by targeting the gut microbiome.

That's next on The Brain-Gut Connection.

EMERAN: We've learned that the microbiome, the community of bacteria and microorganisms in your gut has a tremendous impact on your entire body, including your brain.

Your gut health plays a crucial role in whether you develop typical chronic western diseases such as obesity, heart disease, and cancer.

But did you know that disruptions in your gut health can also affect your mental health?

Poor gut health is contributing to problems like brain fog, attention deficit disorder, depression, anxiety, and sleep disorders.

It may even predispose us to neurodegenerative diseases such as early cognitive decline and Parkinson's disease.

This is all because of the brain-gut connection.

According to a theory by neuroscientist Antonio Demasio, we all have a body- brain-immune system loop that consists of signals traveling from the brain to the body and back.

The brain responds to psychological influences like stress, and the gut responds to what we eat, medicines we take, any infectious organisms and our environment.

The entire system functions like a supercomputer.

It integrates vast amounts of information from within our bodies and from the outside world to generate optimal digestive and brain functions.

This forces us to reevaluate the answer to the famous chicken and egg question.

Are the microbes influencing our feelings and emotions, or are our emotions influencing our gut microbes?

Based on what we've learned so far, the answer is both.

This circular communication may also play a role in your decision making.

People make some of their most important decisions based on gut feelings.

Which college to attend?

Whom to marry?

When to make a career change or retire?

If it's an important decision, humans listen to their gut.

So what's the biological basis of a gut feeling?

It has to do with your brain's salience system.

This system appraises the relevance of the many signals the brain receives, including signals from the gut.

It decides whether it's important enough for you to become aware of consciously.

Like a photographer using Photoshop, the brain uses its many tools and memory databases to refine the quality of the image.

Once this process reaches the frontal part of the insular cortex, the image equates a feeling.

From a neurobiological viewpoint, these are our true gut feelings.

You don't have to go through the time- consuming process of consciously considering all the possible consequences of every decision you make.

That's because your brain makes a prediction based on all the information it has already stored.

This allows you to make decisions more quickly and lets you benefit from past lessons without the psychological burden of reliving every memory.

Remember, because of the brain-gut connection, whatever you do to influence your gut microbes through diet and lifestyle factors may also influence your emotions and gut feelings and ultimately even your biggest life decisions.

The latest research is showing that the brain-gut connection influences more than just fleeting gut feelings.

It's affecting your entire state of being.

The gut microbiome plays a major role in mood and emotions, and alterations in the gut have actually been linked to depression levels.

DREW: Prior to the pandemic, there was a- a big mental health epidemic in America, particularly struggling with addiction, depression, suicide.

These are really at epic all time highs and so put the pandemic on top of it and things definitely got worse.

EMERAN: Several large epidemiological studies have demonstrated a progressive rise in major depression in all age groups with the fastest rise amongst teens and young adults.

Between 2013 and '16, a diagnosis of major depression in teenagers increased by 63%.

There's not a single cause for this problem, but microbiome science has shown that because our brain and gut are so intrinsically connected, our poor gut health may be contributing to the mental health crisis.

A growing number of studies published in the most prestigious neuroscience journals strongly suggests a role of the gut microbiome in several brain disorders, including anxiety, depression, even Parkinson's and Alzheimer's disease.

Fortunately, the latest science is also showing us that improving your gut health through dietary changes can actually change your brain for the better.

In 2014, my research group at UCLA published the first placebo- controlled study showing the influence of probiotics on the gut microbiome and the brain in young healthy women.

After four weeks of daily ingestion of a probiotic mix, we assessed their subjective wellbeing and performed a brain scan to determine if the probiotic had affected the brain.

And to my great surprise, it did.

Brain scans suggested that the women who consumed the probiotics were better able to tolerate exposure to negative emotional stimuli.

This was the first human study to show that probiotics could have a positive effect on the brain.

This leads scientists to believe that diet could play a role in treating psychiatric neurological disorders.

This has even led to a new field in psychiatry called Nutritional Psychiatry.

Dr. Drew Ramsey is a pioneer and practicing psychiatrist in this evolving field.

DREW: I'm really interested in about human connection and therapeutic alliance and then think I'm a- tenacious a little bit.

I want to think about where are the parts of a patient's life or habits that aren't contributing to them really having the best mental health that they can.

And food just becomes a big part of that.

Because, you know, a lot of people feel horribly about the choices they're making.

I don't know how you feel about it.

I would say in medicine we've struggled to get, you know, messaging that is- is really effective and helpful.

People say don't eat cholesterol, but that makes them eat lots of- or guides them to eat lots of processed foods and packaged foods.

And so I think we hopefully doing a better job helping people think more about their brain health in relationship to diet and food.

EMERAN: If you've ever been depressed, you probably recall how sad, discouraged and hopeless you felt.

You may also have experienced symptoms of anxiety like irritability and trouble sleeping and concentrating.

Could improving your gut health ease these symptoms of depression and anxiety?

DREW: If you look at an antidepressant, like a standard SSRI antidepressant and compare it to exercise.

When people are really engaged, not just like a little bit, but like you're doing exercise every day, you're running, you're lifting weights, you're working out, they're equal in outcomes.

And- and what I think that's nice about nutrition and exercise and medications and therapy, see now, when you do all those together, it- it's very, very powerful.

EMERAN: There are now multiple, well-controlled studies that demonstrate an association between altered-gut microbes and the symptoms of depression.

In fact, experts could tell whether patients were suffering from depression simply by looking at the microbiota in their gut.

The microbes identified in some of these studies produce neurotransmitters like serotonin, which is known to affect brain function, emotions and mood.

In fact, our most common antidepressant drugs target neurotransmitters like serotonin and its receptors.

The reason that these findings are so important is that they demonstrate an association between severe mood disorders with an altered gut microbiome.

This is the first step in the development of novel gut microbiome targeted therapies.

DREW: And now we have some data about that.

First of all, there's one of the studies, the HELFIMED trial was the second randomized clinical trial, so really getting to gold standard medicine.

The first was the SMILES trial, 67 patients, half of the group got seven nutritional counseling sessions.

Everyone had depression and was in some treatment.

Like a lot of patients, you know, maybe on an antidepressant, getting some supportive or some, you know, exploratory psychotherapy.

They also added on nutritional counseling.

32.3% of those patients go into full remission.

Number needed to treat is 4.1, which is a- you know, a medicine, that's impressive.

Means like four people come through the door and it's like, "Hey, olive oil, olives, lentils, "eat a more Mediterranean diet.

"I'll see you next week."

Right?

You do that four times.

One person goes into full remission.

EMERAN: In a series of subsequent studies by my group at UCLA, we have provided further evidence to support the existence of close interactions between the gut, the brain, and several chronic brain disorders, including early cognitive decline.

Now remember, the brain-gut connection is a two-way street.

So if your gut health can affect your mental health, can your mental state also affect your gut?

Could your mood and emotions contribute to digestive disorders like irritable bowel syndrome?

Many people are surprised to learn that in some patients, the most effective treatment for IBS is actually cognitive behavioral therapy.

The therapy that is targeted at the mind.

Irritable bowel syndrome is part of a group of disorders that fall in between psychiatry and gastroenterology.

Long viewed simplistically as a gut problem, we now know that your mental state is involved in causing IBS symptoms like chronic abdominal pain and altered bowel habits.

DREW: I think you're talking about patients with IBS who are having a psychiatric component that as you treat the IBS and the gastrointestinal problem, you see the mental health disorder get better.

That- that certainly was true for me when I had gut problems.

(laughs) You know, you wake up anxious, you feel sad.

You're like- you know, you go to lunch and you're worried, because it's really embarrassing when you have an episode.

And so having had some irritable bowel issues here and there over the years, you know, I think that certainly when- when that is better and not active for a patient, their mental health is better.

The correlations, as you know, between mental health disorders like depression and anxiety and irritable bowel syndrome are- are really, really quite high.

EMERAN: The many studies that demonstrate that the brain is immensely impacted by what's going on in your gut and vice versa.

So how do alterations in the gut microbiome lead to brain disorders?

The activation of the gut-based immune system once triggered by an altered microbiome in the gut, this inflammation can spread throughout the body, even reaching the brain.

This is a process called neuro-inflammation, but how can the benign microbes living in our gut trigger such an immune system response in the brain?

In a healthy gut there's a tight barrier made up of cells in a mucus layer that separates the trillions of microbes inside the gut and the millions of immune cells on the other side.

When this barrier is compromised, you have a situation often referred to in the lay press as leaky gut.

There's been a lot of misinformation spread around this term, leaky gut, leading many people to believe there are actually holes in their gut.

That's actually not the case.

Leaky gut actually refers to a thinning of the mucus layer, which allows the microbes inside your gut to come into contact with immune cells.

This triggers an inflammatory response and this inflammation can spread throughout the body and to your brain.

In some people, this inflammation can ultimately lead to the degeneration of brain cells.

We know today that several lifestyle factors can trigger this inflammation in the gut and brain, including chronic stress and by eating an inflammatory diet.

An inflammatory diet is one that is low in fiber, but high in sugar and ultra-processed foods.

ANNIE: Oh, absolutely, I would submit that about 60% of Americans are consuming most of their calories from ultra processed food, and that is the definition of an inflammatory diet.

EMERAN: A diet of ultra-processed high sugar and low fiber foods facilitates the systemic inflammation involving the entire body, including the brain.

Our diet also plays a central role in our response to stress.

The stress we experience in the outside world, but also the stress that our gut and its microbes are exposed to through our modern diet.

STEVE: This connection between threat and a certain kind of immune response probably arose when threats were you know, typically wounding us, but now threats like, can I get my book published or can I get my promotion at work or can I even make it home through LA traffic?

These are the things that are kicking off fight or flight stress responses right now, and we get no benefit from turning on this wound defense response in our immune system.

In fact, this is the- the sort of the recipe for the- you know, the- the plague of chronic disease that afflicts us, that constant sense of precarity, that constant sense of being not safe and of needing to strive every day to try and achieve safety or maintain safety or take care of their families.

This is a curse in- in a physiological sense.

EMERAN: If this sounds like a lot of complicated science, the take home message is simple.

Eating a healthy diet is by far the most important way for the microbes in your gut to produce mood- enhancing neurotransmitters like serotonin and endorphins.

It also allows them to produce anti-inflammatory molecules to protect yourself from widespread inflammation, including inflammation in your brain.

This is a simple reason why what you eat over a lifetime has a major effect on your mental health.

Based on what we know today, we can make some very informed and actionable recommendations about how to keep your brain healthy.

ANNIE: I think when you want to start eating for brain health, you need to think about your brain health mindset.

What is the why?

Why do you wanna age more successfully?

Do you wanna make it to a hundred?

Do you wanna be a- a very active grandparent?

What are your reasons?

It all comes down to the brain health mindset and once you identify your reasons, I think that there's enough information now for us to build a brain protected diet for just about everyone.

EMERAN: There's still a huge amount of science required to fully understand how the microbes in your gut affect your mental health and your brain, but it's becoming more clear that an unhealthy gut resulting from an unhealthy lifestyle has a significant impact on your brain.

Poor gut health can affect everything from your mood to the development of serious neurological disorders.

The good news is that we can make changes to our lifestyle for a healthier gut and therefore a healthier brain.

The simple but powerful interventions you can take right now to protect yourself against depression, cognitive decline, and serious brain disorders.

We'll learn the action steps that you need to take for a healthy gut and a healthy brain.

That's next on The Brain-Gut Connection.

EMERAN: Could improving our gut health help us tackle our current epidemic of chronic disease?

Could our failure to understand the brain-gut connection be the reason why our expensive medicines and surgical treatments have failed to provide sustainable wellness for so many people?

And most importantly, what can you do today to optimize your brain-gut connection so that you can achieve physical wellness and improved mental health?

To answer these questions, we have to go way beyond our modern way of dealing with today's chronic disease epidemic.

A better name for our current healthcare system would be a disease care system.

While the system is highly successful in keeping people alive, it's very expensive and actually very ineffective in making us healthier.

WAYNE: We now have an economic system where an industry makes money off of keeping you alive but not letting you die.

EMERAN: Microbiome science is fundamentally transforming the way we look at chronic diseases and how we can prevent and treat some of the most common healthcare problems.

It is guiding us on a path back to the ancient wisdoms of interconnectedness, teaching us the importance of taking care of our body and mind.

It's refocusing on preventing diseases instead of treating them after they have already occurred.

Dr. Wayne Jonas is a pioneer in integrative medicine, striving to learn how to nurture the body's own mechanisms to achieve health and wellness, using an approach referred to as salutogenesis.

WAYNE: I think salutogenesis is really the foundation of where our health system needs to go and where healing comes from.

So saluto means health, genesis means the creation of, okay.

So it is the simply the creation of health.

That's the science that shows us how health is created.

You and I in medical school, we studied from the book of pathogenesis, right?

And still even now, that's how disease is created.

This is the flip side of that.

This is how health is created and it's always ongoing.

Pathogenesis, salutogenesis are dancing back and forth.

In medicine, we focus on the pathology and let's get rid of it.

In health and healing, we wanna focus on how we create health.

What happens in your body, happens in your mind.

What happens in your mind, happens in your body.

But the brain-gut microbiome connection has now expanded that to the environment.

So now you can't even talk about the brain-body or body-brain interaction.

You have to talk about the brain-body environment interaction, okay?

That is a network, that is a system.

And while the science isolates certain parts of that and you can pull it out and say, "Oh, isn't that an interesting connection?"

When you put that connection back into the web of the brain, mind, body, environment, gut microbiome, now suddenly you have a very complex system that's constantly dynamic and constantly interacting.

EMERAN: This is the science of salutogenesis or whole person health.

And fortunately, it is gaining traction in the medical community, but you don't need to wait for the signs to trickle down through the system before you start to optimize your own brain-gut health.

Achieving a healthy gut and an optimal brain-gut connection is simple.

Take care of your gut and protect your body and your brain.

Your physical health and your mental health.

And automatically you will also do good for the environment.

It's all connected.

So what exactly makes a healthy microbiome versus a not-so- healthy microbiome?

One way scientists are working to find out is to study the gut microbiomes and dietary habits in remnants of hunter- gatherer societies in East Africa and in South America.

ERIKA: In the microbiome field had been studying Americans and Europeans for many years and then our group and other groups as well started looking at these populations that weren't consuming a lot of antibiotics, that weren't eating packaged, processed food.

And when we started looking at the microbiome of those individuals, we realized that our view of a human microbiome was- was very small.

It was very specific to this western lifestyle.

And- and these populations like the Hadza have microbial diversity within their microbiome that's much greater than we see in the typical American, so many more species of microbes within their gut.

However, you don't see, for example, obesity in these populations.

You don't see high levels of cardiovascular disease or many autoimmune allergy type diseases.

So our hope is that by understanding the microbiome of- of all humans on Earth and in- in the context of their lifestyle, that we can have a better idea of what is a healthy microbiome, what are species that are promoting good health and- and if there are species that are really beneficial that westerners have lost because of our lifestyle, are there ways to- to compensate for that therapeutically?

EMERAN: Most of us don't have the ability or desire to move away from western society and lead a hunter- gatherer lifestyle.

And so we're looking for ways to lead a healthier lifestyle right here, right now.

With the explosion of new science, there has been a recent fascination by the public with topics like gut health, brain health, and leaky gut.

With so many people now interested in improving their gut health, different tests and supplements are becoming available on the market.

While I'm happy that more people are learning about the importance of a healthy microbiome, the commercialization of our limited knowledge has gone way ahead of the current science.

Many patients are going out and getting fecal microbiome tests that are on the market and then come to me to explain the results and to ask me which probiotic to take to ease their symptoms.

My answer is simple.

You don't need a fancy microbiome test nor an expensive probiotic pill to improve your gut health.

The path to a healthy gut and a healthy brain is actually quite simple.

What you need to know most are the four pillars of a diet that optimizes brain- gut connection.

One, a largely plant-based diet with a high variety of fruits and vegetables, seeds, nuts, and extra virgin olive oil.

Two, a variety of naturally fermented foods.

Three, moderate amounts of small fish, shellfish and poultry.

And four, the avoidance of sugar and ultra-processed foods.

ANNIE: There are many dietary patterns that have been proven to be brain protective.

The Mediterranean diet, of course, is the most famous one.

And then there's the mind diet, which is a spinoff of the Mediterranean diet, but there's also traditional dietary patterns that come from African American, Latin American, and Asian American cultures that contain the same types of plant-based diet with some fish and seafood.

EMERAN: Microbiome and brain science are growing exponentially and there is much yet to be discovered.

But we do know enough from the current research to recommend actions you can take now to achieve an optimal brain-gut connection.

These are practical, simple and powerful steps you can take today to improve your gut health and therefore your brain.

The first step is to practice natural and organic farming of your gut microbiome.

AVIVA: Probably the most critical thing I think for gut-brain health is to get a wide variety of plant foods in your diet.

And when I say that, I mean eight to 10 servings of different foods that are plant-based a day.

So fruits, vegetables, whole grains, legumes, nuts and seeds into your diet because that healthy microbiome that's fed by those nourishing foods, which also reduce inflammation is so powerful for long- term brain health.

EMERAN: By eating a largely plant-based diet, together with regular consumption of naturally fermented foods, you will maximize your gut microbial richness and diversity.

You will provide your gut microbes with the food they need to create anti- inflammatory molecules and mood-enhancing serotonin.

There are a variety of naturally fermented foods and drinks like kombucha, kimchi, sauerkraut and unsweetened fermented dairy products like kefir, yogurt and cheese.

Depending on your taste preference and availability, you may want to incorporate a variety of these foods into your diet.

And what's important is that you do this on a regular basis.

ROBYNNE: I like to recommend a remove, replace, restore approach.

So the first part of that is remove.

That is to really think about foods, practices, medications that can be damaging to the gut.

The second part is a replace.

And so that involves basic things like exposure to nature where we can replenish our soil microbes, exposure to pre and probiotic foods.

And the final piece restore really involves a lot of mind- body practices that have been scientifically and clinically validated to improve gut health.

So things like meditation practice, adequate sleep, et cetera.

EMERAN: The second key to a healthy brain- gut connection is to eat smaller portions.

ANNIE: Yes, you know, in general, Americans just eat too much food.

One way to cut back on the amount of food that you consume is to eat smaller portions or to reduce the number of hours in the day that you're actually eating.

EMERAN: Try not to eat more than what your body needs to run smoothly.

As you get older, your portion sizes should get smaller.

Think about reducing the size of your portions every decade.

Avoid big meals in the evening when you don't need the extra calories to burn.

You want your gut to switch from a digestive mode to one of rest and internal cleansing.

Another key to improving your brain and gut health is to compress your daily eating time to eight hours.

Keeping your gut empty for 16 hours a day while compressing your eating times to eight hours activates your gut's own effective cleansing mechanisms.

This prevents bacterial overgrowth in your small intestine and optimizes your gut microbial ecosystem.

ROBYNNE: The GI tract actually has a bedtime.

It typically slows down once the sun sets.

So an important recommendation is to stop eating once it becomes nighttime, to allow your GI tract a chance to empty and the products of digestion a chance to get to the finish line.

AVIVA: So I often recommend to my patients that they compress their eating time.

I like to call it time-based eating.

To an eight to 10 hour window depending on what that patient feels like she can tolerate, what you feel like you can handle.

And the most important reason is that our bodies were not meant to eat 24/7.

ANNIE: There's lots of different ways to practice intermittent fasting.

I like the simplest, easiest ways, and that means don't eat after nine o'clock or within three hours of going to bed and delay that first meal of the day until maybe mid-morning.

This gives your- your gut time to rest, and there's also brain-health benefits from not constantly having glucose coming into your bloodstream that your brain basically has to deal with.

The brain goes into cleanup mode when you give it it's- this- this rest.

EMERAN: The next step is really fascinating.

Don't eat when you're stressed, angry or sad.

This is a good example of how the brain-gut connection works both ways from your gut to your brain certainly, but also from your brain to your gut.

ANNIE: Well, I really believe that how we feel about our food has some impact on our health.

You know, I come to this as a physician who is also a chef and a lover of food.

So I believe that eating- the act of eating around a table with family and friends like is very famous in the Mediterranean lifestyle is one way to really cultivate your brain health and your overall health.

EMERAN: Perceived stress and negative emotions don't stay in the brain.

Your gut and the microbes living there will respond to such negative mindsets in a way that is not good for your body or brain.

Chronic negative emotions put your entire digestive tract into a fundamentally different state, compromising its ability to properly digest and process your food.

Another way to eat in the most gut and brain- healthy way possible is to enjoy meals together.

WAYNE: Good evidence showing that the social and emotional environment can have just as big an impact.

For example, the longest study on healthy longevity ever done, done out of Harvard, still going on, when they looked at all the factors that contributed to remaining healthy and living a long time, the biggest factor was social connections, deep social satisfactory connections.

The second biggest factor was meaningful activity.

Doing something that was important, giving back to the- to the community in some way, contributing to society beyond just your own selfish concerns.

Those were the two biggest factors.

Those were bigger than whether you smoked, whether you exercised, what your diet was like.

Not that those lifestyle factors were not important, but they weren't necessarily the most important.

EMERAN: Food is meant to be consumed in social settings with friends and family over good conversations and celebrations.

Eating alone in front of TV, while driving to work or while listening to a business presentation takes away many of the nourishing health benefits of a good meal.

AVIVA: I'm a huge fan of social eating and wherever you travel in the world, and I'm an avid traveler, people eat together.

People eat long meals together where they're not eating quickly.

They're eating slowly, they're having conversations, they're laughing, they're listening, and as we're eating, we're- and socializing at the same time, we're employing a lot of different mechanisms that improve our digestion and metabolism and our assimilation.

We're slowing down, we're chewing our food, we're engaged in a more uplifting environment, which is great for digestion.

And also there's something I think intangible that happens when we share food.

It is such a human social experience that in and of itself we think of food as nourishment, but we forget that that nourishment is expanded when we share it with others.

EMERAN: Another critical piece of the puzzle is to keep your brain and gut microbiota fit.

Studies have shown that a regular, moderate, daily physical exercise schedule of both aerobic and resistance training has positive effects on your brain and your gut.

It slows cognitive decline and reduces your stress responsiveness and depressive thoughts.

In the gut it improves diversity and richness of your gut microbiome.

AVIVA: Exercising outdoors with time in nature adds a whole other level of benefit to it.

You- you get that green space, you get- if you're actually- even something like gardening, you're getting exposed to soil microbiota.

If you're walking in the woods and you're touching plants, so it kind of adds a little plus to the exercise.

EMERAN: The last step to a healthy gut and better brain is to get eight hours of undisturbed, regenerative sleep.

ROBYNNE: Sleep is a magic elixir that keeps our gut healthy and our brain functioning well.

Sleep literally reboots our computer, making that gut- immune connection function properly.

We know that less than eight hours sleep a night is associated with an increase in susceptibility to infection, to cancer, to all kinds of medical problems.

EMERAN: Good regenerative sleep will remove inflammatory substances from your brain and reduce the risk of cognitive decline.

The different sleep phases in your brain are closely linked to the rhythmicity of an empty gut.

Disruptions of your sleep compromise the close interactions of your gut with its microbes.

These are approaches that you can take today.

You can act as an ecosystem engineer and manipulate the brain-gut connection to your benefit.

Far beyond just digestion, the gut also impacts the health of your brain and the quality of our human experience.

It impacts how we socialize with friends and family, how we make decisions, and even how we feel.

With these simple changes, you can help protect your brain from cognitive decline and serious neurological disorders.

You can ease digestive symptoms and achieve better physical health, and you can enjoy a happier mindset and better mental health.

So pay attention to the brain-gut connection, and unlock a future of vibrant health.