>> Hi.

I'm Lewis Howes, New York Times best-selling author and entrepreneur, and welcome to "The School of Greatness," where we interview the most influential minds in the world to inspire you to live your best life today.

And in this episode, I'm joined by Dr.

Will Bulsiewicz, aka Dr.

B., who is a renowned gastroenterologist, gut-health expert, and best-selling author known for his work in making gut-health education accessible.

Dr.

B. explains the critical connection between gut health and mental health, noting that our intestines are home to 38 trillion microorganisms that significantly influence our immunity, our mood, and overall well-being.

He highlights how adding more plant diversity to our diets can heal our microbiome, and emphasizes the importance of facing emotional wounds to achieve lasting health.

I'm so glad Now, let's dive in and let the class begin.

♪♪ ♪♪ Very excited.

There's so many things I want to talk to you about.

The first one being -- being the connection between the gut and the brain and how much gut health actually impacts mental health.

There's a lot of anxiety, stress, overwhelm, mental diseases, or, um, just blurriness, mentally, it feels like, in society today, how much does our gut health impact our mental health?

>> Yeah, well, we've seen these conditions that are escalating -- uh, depression, anxiety, different, um, uh, mental-health disorders, different cognitive disorders, including Alzheimer's disease, Parkinson's, things like this.

And, uh -- And the question is, what the heck is going on here?

changing this quickly, it's not genetic.

So you have to take a step back and say, what is it about our environment, what is it about the way that we live that ultimately is resulting in this effect?

>> Because we didn't have all these mental-health issues 50 years ago.

>> Well, they existed.

They existed, but they didn't exist to the -- uh, the level of intensity or the number of people that are being affected by these things as what we see today, right?

>> Right, right.

>> And these are complex issues.

So to sit here and pretend that this is just this one thing, you know, "Hey, it's the gut microbes.

That's all that matters."

That would be oversimplifying it.

These gut microbes do play a role.

So in order to introduce this conversation, I feel like let's take a quick moment, take a zoom out, and let's talk about the microbiome, which is the -- the living microorganisms that are a part of our body.

There are 38 trillion Microorganisms that exist, covering all external surfaces of our body.

So they're on our skin, on our -- on the top of our head, our scalp.

Literally, they're crossing my eyeball as I sit here and look at you and talk to you.

Um, but they're so small, I can't see them.

So, thankfully, they're not affecting my vision in any way.

>> So these are like little bugs.

>> Little bugs.

>> How many?

30 trillion?

>> 38 trillion.

>> Bugs.

>> 38 trillion.

We call them gut bugs, but really we're talking about bacteria.

>> Bacteria that is around.

>> That's fungi.

>> That's on the outside of our body and our inside of our body.

>> Well, so here's an interesting thing about that.

It turns out that what's inside of our body -- we're talking about our intestine... >> Yes.

>> ...is actually outside of our body.

Yeah.

Bizarre.

I know.

>> Our intestines are on the outside of our body?

>> Okay, so here's the thing.

Your tube is a -- your intestines are a continuous tube.

It starts at your mouth.

Now, you're a tall guy, much like me, okay, but the average person in the United States, somewhere between 20 and 28 feet, okay, is this continuous tube of intestines.

>> 28 feet?

Okay.

>> Yeah, the tube is never broken, alright?

There is no point where things that enter into the tube, leave the tube, and go into the body unless they're absorbed by the body.

>> Interesting.

>> So, basically, what that means is, because it's a continuous tube, it starts at your mouth, which is outside of your body.

Things are outside of your body.

You swallow them down.

You may think of them as being inside your body, but, actually, they're within this tube and they never actually enter into your body.

So all the way through, this is actually an external-facing surface.

>> Interesting.

>> You're interacting with the outside world, which is one of the key points to understand is that you're interacting with the outside world within your intestines.

So this is the reason why, by the way, Lewis, that 60% to 70% of our immune system lives in the wall of your intestine.

This is the home of your intestines.

Like, people may think of the bone marrow as being, hey, that's -- that's where immune cells live.

No, no, they're born there.

They may be born in the bone marrow, but then they move to other places, much like you were born in Ohio and I was born in New York, and now you're here, and I'm in Charleston.

Um, the immune cells move, and most of them take up residence within the lining of the intestines.

And the reason why they're there is because this is actually where we're interacting with the outside world.

And so we need our defense systems in place in that location.

Alright?

So anyway, so here we are.

We got 38 trillion microbes.

Now this is by the way more than we have human cells.

So we are -- yeah, we are less than 50% human.

>> Wait, wait.

[ Chuckles ] How many human cells do we have?

>> About 30 trillion.

>> 30 trillion human cells.

38 trillion, what, non-human cells?

>> Non-human cells.

>> Really?

>> Yeah, so they're clearly outnumbering us.

There is no doubt you are definitely less than 50% human.

And, actually, if we took your 30 trillion cells -- um, if we took your 30 trillion cells and we moved the red blood cells and the platelets, which, by the way, aren't, like, the classic cells.

Like, when we think of cells, I think we all have a picture in our mind of, like, the cell with the organelles, the mitochondria, all these things, right?

So if you took just those cells, you are actually about, um, 90% microbial and only 10% human.

>> And so microbe is not a human element.

>> No, it's not, and it's also not a part of our body.

Um, they take up residence after birth.

>> That's crazy.

>> Yeah, so the water breaks -- the water breaks, uh, Mom goes into labor, and, for the first time, the baby is exposed to the outside world.

And with that come a flush of these microbes.

And actually passing through the birth canal is a gift from nature.

Because as -- as a child passes through the birth canal -- canal for the first time, it's being exposed to this world, this microbial world that dominates.

And they've been around, Lewis.

Um, so, like humans, we've been around for about 3 million, 3.5 million years.

Um, Archaea, which live inside of our microbiome, okay?

They're not bacteria.

They're not fungi.

They're these weird things, but they produce gas, right?

So when you pass gas, think of Archaea.

Um, they -- there's an archaeologic site in Greenland where they found 4-billion-year-old Archaea.

4 billion years.

And we think that that's the oldest life on this planet.

>> Wow.

>> So these -- these microbes, they have been around forever.

They've survived everything that exists.

No matter what happens in this world, no matter what happens, there will be microbes.

They will continue to exist, um, and they're an important part of us as humans, which is really the key point, because, um, we can't be our best selves without our microbes there to support us.

>> Come on.

Really?

So, wait, so how much of our bodies is actually human versus non-human?

What's the percentage?

>> Uh, so human versus non-human?

Clearly less than 50% human.

Okay?

Clearly less than 50%.

Some would argue 10% human.

And then if we were to talk about your genetic code, you are less than 1% human.

>> Come on.

>> Yeah.

>> So what are we?

>> We're a mishmash -- We're superorganisms.

We're superorganisms... >> Wow.

>> ...that are a mishmash of these microbes, and we think of ourselves in isolation like, hey, we're these -- we're these big, strong humans, um, but actually the big, strong humans would be quickly broken down and weak humans if they didn't have these microbes to back them up.

They back us up.

>> If we didn't have these alien organisms crawling over our body, we would not exist, is what you're saying.

>> Well, I mean, we think of them as alien, but they're more native than we are.

They've been around for 4 billion years.

>> Interesting.

>> So -- Yeah.

And so now, with the gut/brain connection -- so the gut, uh, we rely on these microbes.

This is where they live.

They are most concentrated within our colon.

That's their number-one location.

Yes, they're on our skin, in our mouth, in a woman's vagina, all these places, but they're most concentrated in the colon, and they're involved in these core essential parts of human physiology -- digestion of our food, access to nutrients, shaping our immune system, which is inflammation... >> Mm-hmm.

>> ...our metabolism.

On multiple different levels, these microbes are key players in our metabolism.

Um, our hormones.

So, like, for men, androgenic hormones that make us feel masculine, they play a role in that.

Yes, there is -- there are connections between microbes and erectile dysfunction.

Uh, but for women, too, for women, too, it's connected to, um, estrogen and estrogen metabolism and multiple different conditions, including endometriosis, polycystic ovary syndrome, et cetera.

>> Wow.

>> So, um, and then the last part is our brain, um, which is what you started this question with, and -- >> Our gut/brain connection.

>> Our gut/brain connection.

And we can unpack this to describe the multiple ways that those microbes are communicating to our brain, but the bottom line is that your brain clearly has a best friend, and its best friend is your gut all day long, and the brain is taking signals from your gut and adapting to them, but it goes both ways, because the brain is sending signals back to the gut, which can affect the way that we digest our food.

>> Wow.

So can you have a healthy brain if you have an unhealthy gut?

>> Uh, I think that the healthiest -- to have the healthiest brain possible, it is essential to have a healthy gut.

>> Really?

>> Yeah, I think that we need to be quite intentional about the way that we go about these things, because we can kind of just stumble into our health, um, or we can wake up and see that, here we are, and we have 38 trillion microbes.

They're constantly evolving and changing.

The food that you eat today will change your microbiome by tomorrow, and with those choices, you are shaping the microbiome, and that microbiome will affect health throughout your entire body, including your brain, including your ability to function, including your ability to maintain memories, including your ability to focus and get stuff done, and your long-term cognitive health, which includes things like Alzheimer's and things of this variety.

>> Wow.

So if someone is feeling like they have symptoms of some type of mental-health challenge, they're feeling -- maybe they have ADHD or they have depression or depressed thoughts, or they have anxiety or stress or overwhelm, what are three things they could do to start recognizing how to fix them?

>> Well, I'll give you three things, and they all connect back to the microbiome.

Um, I would start with food.

The food is -- The food is our most powerful lever that we can pull in terms of shaping and changing the microbiome.

And there are simple choices that anyone can make, and this doesn't have to fall under a "dietary pattern" or a label.

It's just changing the way you eat.

>> What would be -- for that first one, what would be the top five foods that everyone should eat daily to optimize their gut microbiome?

>> Okay, I can give you a top five, but can I start with this essential rule... >> Yes.

>> ...which is diversity of plants, alright, so eating as much variety of different plants in our diet.

We have to be intentional about this if this is what we want, because the problem is the food system is not going to do that for us.

You go into the supermarket, they've distilled it down to 75% of the calories in our supermarket is three foods.

>> What are those three foods?

>> Wheat, corn, and soy.

>> Wow.

>> Yes, that is 75% of the calories in the supermarket.

Now, granted, most of those are ultra-processed, right?

So I'm here to advocate for real food -- fruits, vegetables, whole grains, seeds, nuts, and legumes.

That's at least five.

We could add mushrooms, alright?

Those are broad categories, and we can get more specific if we want to, but, to me, it's about getting that variety.

>> Mm.

>> And this is not just an idea or a concept.

This is actually scientifically proven.

So in a -- in a study called the American Gut Project, which, by the way, was international, but it was run out of UC San Diego.

Um, they -- what they found is that, at the end of the day, when they did their analysis, above everything else, there was this one rule.

The diversity of plants in your diet was the number-one factor in predicting who had the healthiest gut.

And the number is 30.

30 per week.

>> 30...?

>> 30 different plants per week.

Now, all fruits, vegetables, whole grains, seeds, nuts, and legumes -- >> Include those 30.

>> They count.

>> Okay.

>> All of them, right?

So -- >> So you want to have 30 different ingredients every week of plants.

>> At least.

>> Wow.

>> At least.

But you know what?

>> I don't even know if I've tried 30 different plants in my life.

>> Lewis... >> It's like -- >> ...you and I need to spend more time together.

>> Exactly, right?

It's like, 30?

Wow.

That's incredible.

>> Start a -- Take a smoothie.

It could be Monday morning, okay?

Take a smoothie -- bananas, uh, blueberries, um, greens of your choice, whatever ones you like.

>> Chia seeds, hemp seeds.

>> Chia seeds, hemp seeds, flax seeds.

Um, we're already up to six.

>> Okay.

>> Right?

You want to add in some raspberries or some other kinds of berries.

We could easily get this up to 10, right?

>> Gotcha.

Gotcha.

>> You're making pasta sauce.

Why would you just do pasta sauce?

Why not throw some plants in there?

>> Oh, there you go.

>> Right?

Onions, garlic, uh, basil, oregano.

Um, those count, too.

Spices count.

>> Why is the -- you know, if someone's like, "Listen, I just like my 5 to 10 plants a week.

I eat healthy plants.

I eat mostly plants.

I eat non-processed foods."

Is that good enough, or is it really more about the adding more and more of the diversity as possible, as opposed to just broccoli and spinach by itself?

>> The average person in the United States, 10% of their calories comes from actual plants.

The number-one plant is the potato, right?

We're not talking about optimal nutrition here.

There's a reason why people in the United States are suffering through the health-related issues that they currently have.

We need to make changes.

If we simply added more fiber to our diet, we would radically transform the health of this country.

>> Really?

>> Yes.

And that person who's not necessarily eating a lot of variety but is eating a lot of plants, number one, I give them a standing ovation.

Their diet's great starting point.

They're way better off than the average American is right now, right?

We all, though, We all have opportunities to do better.

So if you take that diet and you add more variety to it, they will reap the rewards of that.

And the reason why is 'cause every single one of these plants has unique properties that are, number one, going to affect our microbiome, right?

So these microbes, they're kind of like us in many ways, Lewis.

Um, they have personalities.

They have -- some of them are -- are not nice.

Um, they have cliques.

They have certain ones that they tend to hang out with, and they work together.

Um, they also have taste buds.

They have different food preferences.

Not every microbe, believe it or not, likes kale.

>> [ Chuckling ] Right, right.

But you can train it to like kale.

Or you can get rid of the ones that don't like kale, I guess.

>> You can train it to like kale, but there's going to be a lot of microbes that are going to be hungry if the only thing that you ate was kale, right?

>> Interesting, yeah.

>> So every single plant is feeding certain families of microbes.

>> Interesting.

So the more diverse and expansive that you have with your plant diversity, the less hungry you'll be, as well, is what I'm hearing you say.

>> Oh, 100%.

>> So if I just eat broccoli and spinach and kale a few times a week versus -- I might never feel like I'm, uh, full.

I never -- It's like I still want more, right?

So I need some different carbs or some snacks or things to feel more full, but if I'm hearing you say it right, if you have more diversity of plants more frequently, you're going to feel more satiated.

You're going to get the fiber that your body needs to be less hungry, as well.

>> Yeah.

So -- So satiation, like, feeling full, um, is an important concept these days, right?

We have all seen the rollout of Ozempic and these other GLP-1-type agonists.

What is this GLP-1 that we're talking about here?

This is a hormone.

It's a gut hormone already produced by your body, right, and makes you feel full.

Now, I'm not sitting here and going to try to pretend that, like, what you eat is going to have the same effect on your body that a drug does.

That's not what I'm trying to do here.

But I want people to understand that here we exist where 95% of Americans, 95% are deficient in fiber.

This is our most prevalent nutritional deficiency, and fiber is what actually leads to the release of GLP-1.

>> GLP-1 is what exactly?

>> GLP-1 is glucagon-like peptide-1, which is a gut hormone, which is what Ozempic is.

Ozempic is GLP-1, okay?

And it has these different effects in our body, including helping us to control our blood sugar and making us feel full.

>> Interesting.

>> Which is the reason why Ozempic is used for diabetes and for weight loss.

>> When someone takes an external drug like Ozempic to create a chemical, I guess, formulation inside of the body, the brain, the gut, the nervous system, things like that to either turn on or turn off certain things, how effective is that versus, you know, having 30 plants a week and just eating the foods that will make you fee-- that will turn on these hormones that you're talking about, that the drug would do and make you feel more satiated and full by itself?

>> So, um, first of all, we have to fully acknowledge that these drugs are highly effective.

Like, there is no doubt that they work.

>> They're getting results.

>> They're getting results.

>> But what are the long-term effects of these?

>> We have no clue.

>> Right.

>> We have no clue.

We don't have the data yet to say what the long-term results of these are.

What we do know with complete clarity is that, if you stop using the drug -- by the way, they're very expensive.

>> Mm.

>> They're very expe-- thousands of dollars per month.

>> Wow.

>> Right?

And are we ready to commit to doing this for the rest of our lives?

Because when you come off of the drug, you go right back to where you were before.

>> Really?

>> Yes, you rebound immediately.

So, um, the flip side, though, I think -- I think it's important, at the same time as we're having this conversation about Ozempic and these types of weight-loss drugs, again, like, I'm not here to vilify them, okay?

But when we're doing that instead of changing the way that we eat -- >> The behaviors.

>> Right.

The -- The -- The problem that exists with this is, like, yes, we can measure weight loss, and when people lose weight, there are different things that can certainly improve, and they become more healthy, but is the only thing that matters for human health our weight?

That is not the case.

There is so much more to, um, us as humans and our determinants of our health beyond just whether or not we're obese, skinny, or what our body habitus is.

And so we need to look at that bigger picture.

The bigger picture is that, when we optimize our diet, we have opportunities to improve ourselves metabolically, which includes improving our weight, which includes improving our blood-sugar control.

But we also have opportunities to prevent other diseases far beyond what Ozempic is capable of preventing.

>> Yeah, but also sounds like -- you know, as I'm hearing you talk about this, it sounds like if someone's taking something like Ozempic to lose weight, if that's their main goal, like, "I want to lose weight, I want to take this drug.

It's going to help me be less hungry," but if someone's losing weight but they're just still eating processed foods and they're not having plants and they're just eating less junk, but they're still eating junk, how would that affect the brain and the gut connection to feeling good beyond just losing the weight?

>> Um, so the -- the -- the data are clear that when we consume an ultra-processed diet, which, in the United States today, 60% of calories are ultra-processed foods.

So more -- more than half.

These are foods, by the way, that did not exist 100 years ago.

>> Crazy.

>> Right?

So, like, what we're describing was not possible for our great-grandparents.

There's no way they could've ate the diet that we currently eat 'cause these foods did not exist.

And our kids, 70% of calories in our kids come from ultra-processed foods.

>> Wow.

>> And there's no doubt that they cause a shift in the microbiome.

It's a shift towards what we call dysbiosis.

So it's the opposite of what we see when we eat a diverse diet.

Diverse diet leads to a diverse microbiome, and that is a healthy microbiome.

When we shift towards ultra-processed foods, we're actually contracting the microbiome, we're empowering the ones that love sugar, we're empowering the ones that create inflammation.

>> And they're signaling the direction they want to go in -- they want you to go in.

"Hey, you want -- you want more of this sugary drink.

You want more candy.

You want more chips."

They're telling your brain, "You need this."

>> There are -- There are interesting studies to suggest that our taste buds and our cravings are driven by our microbiome.

>> Wow.

It's almost like we don't have control sometimes.

Or maybe it's felt in the past, like, "I want this so bad.

Yes, I can stop myself, but my desires and cravings are just, like -- I'm want to go to the store and buy candy right now."

And is that the microbiome kind of signaling and constantly telling us, "Get this.

Go buy this.

You need this."

>> I think that they play a role in that whole -- yes, I think that they play a role in that whole impulse, um, and, yes, that certainly exists, but also the beautiful and exciting thing is our taste buds can change, right, those impulses can change, and you can get yourself to a place where what you crave is actually something that's good for your body and nourishes your body.

>> How long would you say it takes to change your taste buds from not craving sugar and processed foods into craving a diverse, plant-based, healthy options?

>> I think it really -- you really start to see the benefits at four weeks.

>> Four weeks of doing it consistently?

>> Of doing it consistently, yeah, but, by the way, don't -- I don't recommend that people try to flip a switch.

Um, now, there are some people that works for, but, like, to me, we want what -- what I want is sustainable.

>> Mm-hmm.

>> Right?

can actually stick with.

>> Not extremes.

>> Not extreme.

>> We don't want yo-yo.

We don't want to be swinging all over the place, right?

So we want consistency, sustainability, and we want it to taste good.

>> Yes.

>> So start with the stuff that you enjoy.

Introduce simple, sustainable choices, and build from there, right?

And as we start to build, we start to build momentum.

And our microbiome is given a chance to -- to change with us.

So I say four weeks is what it takes to really make this huge change, but, really, I would rather that you do it over the course of six -- six months, a year, right, because then, by consistently doing this, you are actually going to completely reshape your microbiome.

>> Wow.

>> So getting back to the question about, you know, ultra-processed foods and -- um, and brain health, um, what you're going to create with these ultra-processed foods and inflammatory microbiome -- and inflammation is an essential feature that exists in many different cognitive disorders and mood disorders, including depression, including anxiety.

So, from my perspective -- >> So you say inflammation influences anxiety and depression.

>> Oh, 100%.

>> How much would you say -- sorry to cut you off there, but how many -- what's the percentage of the human population, would you say, has an inflamed gut and brain?

>> Oh, gosh.

Um, it's hard to put an exact number on that, but I think what we see, if we were to zoom out -- >> Even in America, then, maybe.

>> Yeah, in America, if we just focus on what's happening here in the States, if you zoom out for a moment, think of all of the digestive disorders that exist, so -- >> Obesity, digestive disorders.

>> Metabolic issues, immune issues, meaning autoimmune-type issues that are, like, hugely on the rise, um, hormonal issues, right, and you go down the line, and you think of these things, and I haven't even gotten to the brain yet.

>> Heart issues.

>> And basically what I'm saying is the gut microbiome is a player in all of these different conditions.

>> Wow.

Wow.

>> So if the gut microbiome is a player in these conditions and you have these conditions present, you've already proven -- you've already proven what the state of the microbiome is.

And then the question is, how is it affecting your brain, right, and could you could you have better energy, better focus, better ability to do, um, tedious, hard things during the day?

And the answer would be yes.

And the way that -- that starts is by changing -- changing your diet.

>> Wow.

>> On food real quick before we move on, there's a study called, uh, the SMILES trial... >> Okay.

>> ...where they took a plant-predominant, not -- it was not vegan.

It was a plant-predominant Mediterranean diet.

>> Uh-huh, so it has some -- some fish and shellfish, things like that.

>> 100%.

And it was, um, as effective as medication for the treatment of major depression.

>> Really?

>> Yeah.

>> Just putting them on that nutritional food plan?

>> Yes.

>> I try to keep correcting myself to being, like, "What's the healthy food plan?

What's the nutritional abundance plan that we're going to step into?"

>> Abundance is the right word for what we're talking about here.

30 different plants or more.

I'm asking you to add more variety, not take away, not restrict.

So it's the opposite of what we've been told by traditional fad diets.

>> Yes.

>> The choices that you make today will have an effect on your microbiome by tomorrow.

So, for the listeners at home, be optimistic that you can make a small choice, and these small choices may seem trivial in the moment, but guess what?

If you were to come back and do that again tomorrow and the next day, this actually small choice will become a massive and powerful choice for your health.

Don't wait Do it now.

>> That's incredible, man.

We hope you enjoyed this episode and found it valuable.

Stay tuned for more from "The School of Greatness" coming soon on public television.

Again, I'm Lewis Howes, and if no one has told you lately, I want to remind you that you are loved, you are worthy, and you matter.

Now it's time to go out there and do something great.

If you'd like to continue on the journey of greatness with me, please check out my website lewishowes.com, where you'll find over 1,000 episodes of "The School of Greatness" show, as well as tools and resources to support you in living your best life.

>> The online course Find Your Greatness is available for $19.

Drawn from the lessons Lewis Howes shares in "The School of Greatness," this interactive course will guide you through a step-by-step process to discover your strengths, connect to your passion and purpose, and help create your own blueprint for greatness.

To order, go to lewishowes.com/tv.

♪♪ ♪♪ ♪♪ ♪♪