The Hidden Half Of Nature: Why Invisible Microbes Are The Key To Health & Life.

In this episode of the Ben Greenfield Fitness Show.

If you think of a grain of fine sand, that's about as fine an object as we can see with the naked eye, and that's down in that sort of millimeter kind of scale, you get smaller than that, we can't detect them with our own senses. So nobody's ever seen a microbe without technological assistance.

We're eating plants that are not only deficient in the basic essential minerals like Dave talked about, zinc, calcium, a little bit of copper, and so on, they don't have nearly the level of phytochemicals coursing through what we call their green bodies.

He's an expert in human performance and nutrition, voted America's top personal trainer and one of the globe's most influential people in health and fitness. His show provides you with everything you need to optimize physical and mental performance. He is Ben Greenfield. Power, speed, mobility, balance, whatever it is for you, that's the natural movement. Get out there. When you look at all the studies done, studies that have shown the greatest efficacy, all the information you need in one place right here, right now on the Ben Greenfield Fitness Podcast. Hey folks, it's Ben Greenfield here. And as I've mentioned on the podcast before, I read a lot of books and plenty of those books are about gut health and the immune system and alternative medicine. You know, these are topics that I really dig. And one of the best books that I discovered just randomly when my brother in law gave it to me for Christmas actually in the past several months was entitled the Hidden Half of Nature, the Microbial Roots of Life and Health. And at first when I looked at this book, I thought it was just going to be about gardening and perhaps a little bit about, you know, nature and soil and things along those lines. But when I delved in, I found it to be be full of brand new insights that I hadn't discovered before. Insights specifically into microbes and how they affect not only our bodies, but also the food that we eat and the environment that surrounds us in a very intimate way. And I found the book absolutely fascinating, especially when it comes to the, the human gut and how we're really not what we eat, we are the product of what our microbes eat. And this just sent my head spinning as I began to delve into this book. And it does things like draws parallels between, say, a plant and the roots that it puts down into the soil and our own guts that almost act very similarly to a root. It delves into agriculture, medicine, soil and beyond. After reading it I decided I had to get the authors on the show because I think that you are really, really going to get a lot out of not just this book, but also what the authors discovered while writing this book. So my guests today are the authors of the Hidden Half of Nature, David Montgomery, and Ann Bickley. And I'm hoping, Anne, that I'm pronouncing that last name correctly. Am I? Okay?

Yeah, that's good. Yeah. Bit Clay. You got it.

Bit Clay. I'm good, I'm good. And Montgomery, of course, was far easier. So welcome to you also, David.

Thank you. It's a pleasure to be here.

Yeah, absolutely. Now, for those of you listening in, if you want to access the show notes as you listen, and if you want to access the resources for everything that Dave and Ann and I discuss, you can just go to BenGreenfieldFitness.com Hidden Half. That's BenGreenfieldFitness.com hidden half so, that being said, Dave and Ann, I'm curious how you first became interested in this topic in the first place, this topic of microbes.

Well, you know, we kind of backed into it. We had started writing a book that turned out to be a different book, and we, we were focused on looking at soil restoration. I'm a geologist, Anne's a biologist. We were trained in the sort of the natural history disciplines that study the world we can see around us in our everyday lives. And so part of what we tell in the book is the story of how people like us would actually become aware of the importance of microbial life as the foundation for good health, not only just in the soil, but also in our own bodies. And so the book takes us on the journey that goes through there. But the story really started in our yard when we bought a house in North Seattle, where when we peeled the lawn back to try and put in the garden that Ann so desired, we realized we had really bad soil. There were no worms in it. There was hardly any life in it. And gradually, over time, we restored the yard, starting from the ground up, literally from bringing organic matter back into the soil and looking into the mystery of how did adding dead stuff, organic matter leaves and wood chips and coffee grounds, how did that catalyze a rapid explosion of life above ground? It was looking into that mystery that really got us delving into the world of microbes and starting to realize just how powerful and important and transformative they can be for the health of the world around us, our soils, and also ourselves.

So you basically just had like a barren wasteland in your backyard that you had to figure out how to make grow so that you could basically garden and grow food.

Yeah, that's right. And in fact, Ben, on our website, which is dig the number two, the word grow dot com. So that's dig2grow.com There is a photo of that soil after we had taken off all the existing vegetation on our lot. And I mean, we kind of did the opposite of what's happening in Seattle. Everyone's tearing the house down, rebuilding, and we left the house, but we scraped every last grass blade and whatever was here off, and we got a good look at our soil. And it was pretty bad stuff. It was filled with rocks due to Seattle's glacial legacy. And it also was just this anemic, the most anemic color you can imagine. It was sort of like a beach sand color. And so when you look at that and you think, ugh, how is anything ever going to grow in here? Well, yeah. Then that quickly took us into the world of organic matter and compost and microbes.

Now, before we get into defining what a microbe actually is, I thought it was kind of interesting how you almost created like this home brew that you dumped all over your garden garden to essentially build up the microbial diversity in there. Can you go into what you actually were dumping into your garden to change the soil?

Yeah, well, you know, this is a state that likes to brew a lot of things, beer, and we're a big fermented food place. And it turns out that you can brew something that's called compost tea. So this isn't anything new. This is something that people had done a long time ago. And then we stopped doing it. I think probably more or less the advent of a lot of modern fertilizers and that sort of thing. The way to do compost tea is you get a five gallon bucket, you fill it with water, you let the water dechlorinate over about 24, 48 hours. Then you get like a nylon type thing to hold two to three cups of worm compost, and you suspend that in the water and then you put an aerator in the water. So imagine, you know, basically a glorified fish tank aerator. I had a special one that I purchased from a compost tea outfit. And you turn the aerator on and you also put in some nutrient solution, right? Because in that worm compost is a whole world of, you know, bacteria. There's probably viruses in there. Who knows, there might even be some archaea in there. There's probably some fungi in There. And all of these microorganisms need to eat. And carbohydrates are a good source along with some mineral nutrients. So I got my water going. I've got the bag of worm compost in there. You want that worm compost. You don't want it spinning around in the water. That's why it's enclosed in a sock through which the water can flow and swirl around. Turn that on and within about 12 hours, you've got a really nice head on your compost tea. It looks like root beer foam or beer foam. And it smells nice too, I have to say.

Interesting. So you just dumped this all over your garden and you were able to witness the soil change?

Yeah, well, in some cases I would water it in with the watering can. In other cases I had a sprayer. So I would, I would spray it on particular plants, for example, roses. I didn't really, not. I don't really consider myself much of a rose person. And then at some point in your life, you start to see roses like they're this completely different plant and you've got to have them, but they're, they're also the kind of plant that can be kind of susceptible to some leaf pathogens, some molds, some molds and fungus. And they, they looks like someone's taken, you know, a cigarette to your rose leaves. They all look like they got burnt holes in them. Well, I'd spritz those with compost tea and bingo, that stuff was gone. And then if I, if I stopped using the compost tea, those things would come back. So that's one of the more concrete examples of how we know that the plants were benefiting from the compost tea. I wish we had been able to do some kind of a microbial, you know, soil life analysis, you know, a before and after.

Right.

Unfortunately, we weren't able to do that, although we just recently, last couple weeks, are working with a soil scientist who got samples of soil from different places in the garden, is going to test them out for organic matter content.

Okay.

Yeah.

Cool.

That's the brew.

Yeah, I thought it was interesting. Or you're just dumping this stuff all over your garden to change it. And I've witnessed my wife also literally transform entire sections of a yard. We used to live in a little rancher home. She dug up the entire backyard and transformed it into a thriving garden with plants that were towering over our heads as we walked back there and literally fed our family out of the back of a tiny little quarter acre backyard just by taking composting classes and changing the microbial diversity of our own soil. And even, folks, if you're listening in and you're not into gardening or you're not into soil and you're not interested in this at all, perhaps you're just interested in the way that you feel in the morning and the way that you poop. Don't worry, this is going to tie into all of that here shortly. But before we delve into how this can apply to your own body and your gut, Ann or Dave, how would you really define find a microbe? Like, what is a microbe?

It's actually pretty simple. It's a life form that's too small to see with the naked eye. So it's things that are smaller than about a tenth of a millimeter or so. You can, if you think of like a grain of sand that's getting down a fine sand that's about as fine an object as we can see with the naked eye, and that's down in that sort of millimeter kind of scale, you get smaller than that. We can't detect them with our own senses. So, you know, nobody's ever seen a microbe without technological assistance. But that's basically. Basically how you define them is it's the invisible part of nature. And if you add up the total weight of life that's in the microbial world, that invisible part, it's about half of nature. And that's how we came up with the title of the book.

Okay, gotcha. So these microbes, you know, you go intoit's really fascinating, the whole history of how they were discovered, et cetera. We've got a lot of listeners who drink wine. And so I was curious if you could go into part of the discovery of microbes and how that ties into the winemaking process. I thought this part was really fascinating.

Well, you know, winemaking is an ancient art. It goes a long way back. But it wasn't until people really sort of figured out that it was microbes that were doing the fermentation that took. When was that? The 1830s or 40s, I think it was. But that's the nice thing about writing a book. You write stuff down and you don't have to remember it. You can go look it up in the index.

Exactly.

But the Louis Pasteur was one of the people who was involved in really discovering and convincing people that the mystery of fermentation, how beer and wine were made, was actually due to these tiny little alchemists that we know today as microbes. And there's Interesting stories about how he sort of figured it all out that we go into in the book. But it was quite a surprise when microbes were first discovered, when they first observed in sort of homemade microscopes in the 17th century, the guy who discovered them, Antony van Leeuwenhoek, really didn't think that they did anything. They were these curiosities. And it took almost two centuries before we got around to realizing, oh, no, they actually do things. And one of the first things we discovered that they did was that they. All the beer in Germany, all the wine in France, was actually not made by brewers and vintners. It was being made by microbes shepherded along by human intervention. But it was the microbes who were doing the heavy lifting. And it even turns out that today you're familiar with the idea of terroir, the idea that where you grow the grapes will greatly influence the character and flavor of the wine that comes out of it. And it turns out that a lot of that is actually microbial mediated. And it's not that the soil doesn't matter or the climate doesn't matter. They do. But they are shaping. They help shape the microbial communities that live on the wine grapes that then get onto the skins and into the. Into the fermentation process. And so microbes are. You know, the next time you have a nice glass of your favorite wine, you know, you might consider thanking the regional microbes as much as you might thank the regional soil or climate of wherever you bought it from.

So. So if changing up the microbial diversity or the microbial composition of the soil can affect something like how a wine tastes, you know, the terrar of a wine, how do we actually extend this into what conventional or modern agriculture is doing as far as soil is concerned? And I realize this may be a little bit of a deep discussion. I'm okay with delving into this because obviously people are interested in how the food that they eat is affecting their bodies. And much of the food that we eat is, of course, grown in soil. In terms of the way that soil and microbes interact, what is it that conventional agriculture is doing wrong when it comes to microbes in the soil and how that affects the foods that we eat.

Yeah, we could have quite a discussion on this, and it was one of those very interesting areas that we delve into in the book. But the real sort of thing that helps to explain why there's even any effect at all boils down to the very curious observation that plants will push out of their root system up to 30 or 40% of the Photosynthate, the things like carbohydrates and organic molecules they manufacture with their monopoly on photosynthesis. So taking carbon dioxide and water, putting them together to make sugars and other organic molecules, plants will push a good deal of that, a third to up to 40% out of their roots into the soil. And at first blush, that just doesn't make any sense. Why would a plant do something so utterly wasteful as to, you know, leak all this great stuff they make into into the soil? But it makes a lot of sense, if you think about it, that they're actually feeding the microbes in the soil. And why would they do that? Well, those microbes are taking those exudates, as we call them, that the plants push out into the soil and they consume them because it's basically pushing out party food sugars into the soil, microbial party food. And the microbes consume that stuff and they turn that into metabolites. They excrete their waste products, some of which are very beneficial to the plants. And the plants will then take those back up. And they can be things like plant growth, promoting hormones, other compounds that assist in plant defense, of repelling insect pathogens or herbivores that nibble on their leaves. There's all kinds of things that the microbes in the soil are producing that benefit the plants, that serve as their host and that serve up sugary diet to feed the microbes. And that's a classic example of a symbiosis. There's two organisms whose activities help both of them. They're mutually supportive. And so how does this all relate to conventional agriculture? Well, if you think about many of the things that those microbes are providing to the plants, it's things like phosphorus, it's things like nitrogen, it's things like micronutrients, the elements from the soil that are derived from rocks that get broken down and brought into the plants. And it turns out that mycorrhizal fungi are very good at going out and finding very particular mineral elements like phosphorus, like zinc, like iron, and bringing that to the plants and trading it for those sugars. And the bacteria that live in the zone called the rhizosphere, a zone of life around the soil, around the root tips, where there's a lot of soil life precisely because of these exudates that the plants are pushing out. The bacteria in that zone are also producing things that are good for the plants. So the way that a connection to how we grow crops comes in is that if we start adding A whole lot of say, nitrogen and phosphorus and potassium to the soil. The sort of the big three of the NPK of the fertilizer world. We're basically spoon feeding plants the major nutrients they need to grow and get big. And they grow and they get big. Fertilizers are called fertilizers for a reason. They work particularly on degraded soils that don't have a lot of organic matter. But we could go into that as well. But the key thing is that when you basically spoon feed plants the elements that they need to grow, that doesn't mean they're going to be healthy because they're not getting the full complement of the micronutrients. Why? Well, when they get spoon fed the major elements they need, they cut down on the exudates that are feeding all those soil microbes. So their microbial allies in the soil starve and they don't have as much input. They're not going to be going out and scavenging as much zinc, as much iron, as much the little bit of copper that plants actually need to grow, for example. So when we it effectively an over fertilized environment turns our plants into botanical couch potatoes where they're not really doing the things that will get them the other nutrients that they need for good or optimal health. And the other aspect of conventional agriculture is the plowing, which disrupts and breaks up all the mycorrhizal fungi that are, that are bringing those nutrients to the plants.

Okay. So basically when modern agriculture is using something like fertilizer, the end result is that the interaction between the microbes in the plant results in the plant actually being poorer in specifically it sounds like most crucially, minerals.

Well, yeah, it's not just the minerals, it's also something else that's pretty important. So the other part of modern agriculture that affects the root microbiome in particular is the use of all of the, you know, the pesticides, the fungicides, rodenticides, any, you know, all these biocides, they do what their name says, they kill life. So in addition to not being fed plant exudates, the microbial world beneath our feet is taking a hit because they're being, you know, directly poisoned. And the poisons go hand in hand with the fertilizers because with plants shutting off the exudates to the microbes and taking all their nutrients in through fertilizers, they've also given up. Plants have also given up something else and that is that they stop producing phytochemicals. And so these are all these this is like the thousands of compounds in a plant that is like their arsenal against pests and pathogens. So when they stop producing the phytochemicals, this is also another area where this begins to affect our health. So we're eating plants that aren't. They're not only deficient in, you know, the basic essential minerals like Dave talked about, zinc, calcium, a little bit of copper and so on, they don't have nearly the level of phytochemicals coursing through, you know, what we call their green bodies. And it turns out phytochemicals are important for our health. So we're eating these wimpy couch potato plants and we wonder why we get sick, why we have ailments, you know, why our immune systems aren't. Aren't powering up when we need them to power up.

Gotcha. So basically, phytochemical and mineral poor plants would be the result of a soil that hasn't been treated properly in terms of enhancing the microbial diversity of that soil. Now, in terms of increasing the microbial diversity of the soil, what would you say would be kind of like the ultimate scenario to actually grow food in an ideal soil? What would you do to the soil? What would you not do to the soil to increase the microbial diversity or to ensure that you're not creating a plant or a food that's low in phytochemicals or low in microbes?

Well, that's a great question. And that's what I've been working on for the last year. Last year, after we got the hidden half done, that very question was burning very highness. And in the hidden app, we go into the argument that bringing organic matter back into the soil and increasing soil organic matter is a recipe for doing that. So how would you do that agronomically? How would you do it on a farm? Say, you know, it's whether a small farm or a huge farm.

So when you, when you say small farm, that could even include like someone listening in who's like a patio gardener or a backyard gardener.

Oh, yeah. Oh, yeah. Yep. Absolutely. And what I discovered in spending about six months going around the world visiting with farmers who were doing this at different scale operations, and having watched Ann do this in our yard myself, to our patio garden operation really boils down to three simple principles. And those principles are at the heart of what's called conservation agriculture and what the UN calls it. And those principles are, one, don't disturb the soil. Basically, if you plow the soil or you turn the Soil over, you basically break up those mycorrhizal connections with the plants. It doesn't benefit the fungi that are actually helping nourish the plants. The second is to plant cover crops, and particularly cover crops that have legumes that will help fix nitrogen, where they have microbial partners that will capture nitrogen from the air and turn it into botanically useful forms. And then third, to grow a diversity of COVID crops and to rotate crops on the same piece of ground. In other words, don't keep growing corn and soy, corn and soy in the same order in the same place over time, because the pests and pathogens figure that out, and then you're right back on the agrochemical treadmill to try and manage those problems. But the farmers that I visited that are practicing those three principles have been rebuilding their soil, increasing their organic matter, and it works for a pretty simple reason. Those three things taken together are feeding the microbial life. So it's kind of like a kickstart back to microbial life, like Ann's compost tea in our yard, where we're basically feeding and brewing up microbes, but doing it in the soil with our farming practices. And what got me excited about this visit to farms around the world is that those practices are working very effectively on small scale subsistence farms in Africa, small family owned coffee plantations in Costa Rica, large cattle ranches in the Dakotas, and corn and soy, well, corn, soy, and then cover crop and wheat farms in Pennsylvania and Ohio. These ideas scale, they actually work independent of the technological level you have at your disposal as a farmer and independent of the size of the farm. They could, you know, if they were adopted universally, they could truly transform agriculture in ways that would not only allow us to grow just as much, if not more and more healthy food, but it could also park a lot of carbon in the soil and could help conserve biodiversity on that quarter of the world's continents that are now dedicated to agriculture.

Does this stuff affect meat? I mean, for example, if you've got, like, cattle that you wind up eating, like beef that you wind up eating from, cattle that's grazing on plants grown in soil that, say, doesn't have microbial diversity versus soil that does, is there any effect, or do you know if there's any effect on the actual meat for people listening in who are eating not just plants, but also hamburgers?

Yeah. I mean, it sort of stands to reason, doesn't it, Ben, that if we know that the nutritional quality of a plant depends on the kind of soil that it grows in and Then you've got whatever ruminant you want, you know, to pick. Cow, goat, whatever. The nutritional profile on that animal is going to reflect what the animal is eating. So if you've got, you know, grass fed, naturally pastured animals that are in a pasture that has not, you know, that, let's just put it this way in the positive, where that pasture has a rich microbial diversity down in the rhizosphere of all of those grass plants, every blade of grass that that cow or that goat or that sheep eats is going to have a full complement of minerals in it. And then that in turn is going to get incorporated into the animal's muscle tissues. So we know, for example, beef, let's take beef, beef has iron in it and we need iron in our blood cells because it's part of how our body captures oxygen with that heme molecule. You want to make sure that the beef that you're eating has eaten grass that has its full complement of minerals. This is one of the reasons, among the reasons that, you know, getting back to both grass fed and organic meat is better for our health. If you're choosing to eat meat, that is, if you don't eat meat, then, right, you're not even going to really be concerned with this. So along with the fact that there's not antibiotics in organic, you know, organic farmers are not feeding antibiotics to their animals. So that's how what a cow eats, the quality of its food, affects the nutritional quality of the meat.

One of the things that has been shown by some studies of foods since the 1930s and 40s are the decline in the micronutrient concentrations in fruits and vegetables, but also in meat and milk and dairy. You have to eat more of the same foods grown today when they're conventionally grown than you had then. You needed to eat back in the 1940s and 50s to get the same complement of micronutrients. You can get the macronutrients, you can get the, you know, you can get the major elements. And if you look at, say, a tomato, you know, if you grow a tomato, no matter how you grow a tomato, the basic bulk element chemistry is pretty similar for the major elements, but there's big differences in the micronutrient concentrations that come through and that have been tracked in studies over the last few decades. But a lot of those studies are just looking at sort of conventionally available typical foods. There haven't been as many studies that have looked at sort of long term profiles and nutrient density depending on how the food was Actually grown.

Got it, got it. So I'd like to kind of like switch perspectives here and talk a little bit about the human body and how this ties into the human body, specifically, starting with the area that you talk about quite a bit in the book, and that is the colon. And before we get into microbes in the colon, can you outline why it is that the colon is so important when it comes to our immune system and our health and the way that we feel?

Yeah, yeah. Isn't it interesting? We never used to like to talk about our colons. I think through podcasts like yours and books like ours and so on, it's becoming a more and more popular topic. And when you start to look into that, at least maybe in my circles, let's say, but when you start to look into that, I think there's a very good reason for it. So our colon, if you picture there's illustrations in the book and there's, you know, one of, one of them is the digestive tract. And up at the top, of course, our mouth descends down into our stomach and then you know, all the sausage looking loops of the small intestine and then that sort of inverted U shape that you see in all of these pictures of the body. And that's, that's our colon, also called our large intestine. And the colon is very interesting for two reasons. I think first of all, the lion's share of our microbiome. So that's all of the indigenous microbial communities that are in and on our body. The lion's share lives in our colon. So what we've got down there, you know, that's our Amazon, that's our Pacific Northwest rainforest. That is the creme de la creme of the biodiversity that is our bodies down there in the colonial. So to me as a biologist, that's like, oh, okay, this is a place I'm going to go, you know, learn more about. I want to know what's happening down there. And the other interesting thing is that our immune system, so this is, you know, our immune system and immune cells. This is what takes care of us. This is in plants they call it a defense system and us call it our immune system. This is our T cells and our B cells and our macrophages. And these are all these cool cells that travel around our body, keeping an eye out for any, anything that's gotten in that shouldn't be there. And about 80% of our immune system is wrapped around our digestive tract. And of that 80%, the lion's share Again, is around our colons. So you just sort of put those two things together and all of a sudden you've got a really interesting ecosystem happening down in the colon. And in some respects it makes some sense. Everything that we pull into our bodies from the outside environment, I mean, it comes in, say, through our, through breathing air and so on. But really most of what we bring into our bodies from the outside environment comes through our digestive tract. So from that standpoint. Yeah, that's where you want the overlap.

Got it, yeah. So there's two different concepts you talk about regarding the colon that I'd love to hear a little bit more about because I think this would be fascinating for folks. One is this idea of something called galt, G A L T. Can you explain what that is and why that's important, especially when it comes to our immune system and our colon?

Yeah, so GALT stands for gut Associated lymphoid tissue. And that's just this. That's just the fact that most of our immune system is associated with our gut. And the reason for that is in addition to. So I talked about the colon being like the Amazon, the Amazon rainforest equivalent in our bodies. And our immune system is very snoopy and is very nosy and it wants to know what is going on in the colon. And you know, initially, let's say, you know, in the earlier days of immunology, most people thought, Most immunologists thought, yeah, our immune system is there to kill pathogens and to, you know, so that's say the tb, the TB bacterium, or any number of other things that cause infectious disease. And while that's true, that that's what. Partly what our GALT is up to is tracking down these pathogens, it's also inspecting just as carefully our microbiome. Now, the microbiome we obviously haven't. That's a new term. We haven't really done due diligence until maybe just the last decade or so on looking into our microbiome and learning about all of the microorganisms that compose it. Well, most of our microbiome, it helps us far more than it harms us. And the way that it helps us has to do with our immune system. There's some great illustrations in the book. There's a type of immune cell that's perched right outside of the colon wall. And this immune cell is called a dendritic cell. And it, and only it, it's sort of shaped like a starfish. And it can take one of its arms and move it, get this listening Move it right in between two colon cells. And like a periscope, it surfaces on the inside of a person's colon. So it's looking around, it's going to grab a sample. And what that sample is called is, it's called antigen. And the antigen is really important to our immune system because it's how our immune cells know whether or not something is a pathogen that they need to get all fired up about, go after, or whether this antigen is say, some kind of a molecule that a member of our microbiome is making that activates some other part of our immune system. So what we've come to see between the microbiome and the colon is that the microbiome is in many ways just this information service for our immune system that is distinguishing between friend and foe. But it turns out it's also helping our immune system regulate our inflammation levels. Because there's certain members in the microbiome that contain antigen that will activate kind of an immune cell that is an anti inflammatory immune cell. So we know today that most of what ails those of us in the western world are these various chronic and autoimmune diseases and conditions. So when you've got, say you're missing some members of your microbiome, maybe you're not eating a kind of a diet that really promotes these abundant microbial beneficial populations in the gut. That means that when your dendritic cell goes to look for antigen from some member of your microbiome, it's missing. If that microbe is missing, that antigen is missing. When the antigen is missing, that anti inflammatory immune cell is not going to get activated. And then what happens over time? None of this stuff happens overnight. Over time you then have this imbalance where the pro inflammatory immune cells are basically kind of running amok in your body and they're creating this very low level. It's probably not noticeable to us in the way that say inflammation is involved in wound healing, but you've got this low level of inflammation systemically throughout your body. And what we know about that is that it's pretty damaging to cells and tissues to have that be going on day in and day out. So that's, that's sort of the, you know, connecting the dots from the GALT to what is on the inside of our colon, to how the microbiome communicates with the immune system to keep us, to keep our, our inflammation process normalized. Because you want it always at the ready if you've got some pathogen, but you also need it to be, you know, backed off when we're just, you know, walking around day to day and not encountering any threats or anything.

Got it. So. So it. Would it be safe to say then if someone actually does not have microbial diversity in their colon, not only are they not going to be able to fight inflammation, but they're also not going to be able to adequately mount an inflammatory response?

Yeah, that's probably fair to say, at least in so much as we know the mechanisms by which the microbiome is communicating and modulating and informing what the various immune cells do. It just. Yeah, that's pretty much it. Because if you've got, it's sort of like, you know, think about a band or an orchestra. You know, you got the trombone is missing and the tube is missing and all of a sudden your horn section is all fouled up.

Got it.

You know, and that throws the whole orchestra off. So that's, you know, that's kind of the operating hypothesis behind a lot of the chronic and autoimmune conditions is that we appear to be missing some of our microbes.

So in terms of this whole idea of microbial diversity in the colon, are there ways that people can actually increase their microbial diversity? Is it as simple as taking, for example, a probiotic? Are there things we can learn from the plant kingdom or the composting kingdom when it comes to increasing microbial diversity in the colon? I mean, what have you guys discovered as far as how we can actually affect microbes in the colon?

Yeah, you know, Ben, I would really love to say, oh, wow, there's these, you know, this brand new thing, and it's shiny and it's bright and we all need to have it and that's going to increase our microbial diversity. But as it turns out, the thing that most increases the microbial diversity in our colon is something that we've known all along and we've kind of lost sight of it. And that is the very foods that we send down the hatch. And so this is where the microbiome begins to explain some of the benefits of a plant based diet. There's an enormous diversity of plants across this planet. And we are omnivorous creatures and we can eat and we do eat anything. And so when you eat a diversity of plants, you're sending down into your colon not only the complex carbohydrates of which plants are made, but also the phytochemicals that are in plants. And as we mentioned, there's thousands of different kinds. And in part, some of these phytochemicals are bound up in the cell wall of plants. And so they become components of fiber. And that fiber is what our colonic microbiota ferment. And so every time you're eating a different plant, you're feeding a different kind of microbe and probably a different kind of community down in your gut. And remember, I talked about that being the most biodiverse place in our bodies. We cannot be eating a monoculture of things, whether it's lettuce or hamburgers. That does a huge disservice to our microbiome. The way to cultivate this diversity is to be eating a very diverse diet. And, and there's just many, many more plant foods to eat than there are animal foods. So we, the way we eat now is, you know, we haven't sworn off meat, but what lands on the plate first is plant foods. And if we can get two or three different plant foods into a meal, we will, you know, and so that, that's sort of how we can get down to having a diverse colonic microbiota. And we know that what happens, you know, Dave talked about these metabolites that bacteria produce in the rhizosphere right around the root. And it turns out that the microbiome in our gut, it gets. What it does with these plant foods is just fascinating. It's also creating microbial poop that to our bodies is absolutely medicinal. And there's a group of compounds called short chain fatty acids, one of which is called butyrate. And if you delve at all, if your listeners delve at all, into the microbiome, it'd be really interesting for them to just read up a little bit on all of the things that butyrate, a microbial poop basically does for our bodies.

Interesting. So it turns out that basically one of the best things that people could do, and I've heard this before, cycling probiotics. If you're taking probiotics, like switching from brand to brand, using different types of yogurts, and also if you're eating fermented foods, not just using, say, sauerkraut, but also things like kefir or natter or kombucha, basically introducing a wide variety of fermented foods into the diet, it sounds like the same could be said for plants. Like, if you're just like a tomato, carrot, lettuce person, branch out and eat kale and bok choy and purple cabbage and cilantro, and basically introduce as many different types of plants into the diet to increase microbial diversity, it would have.

The Added benefit of being a more enjoyable diet, too.

Yeah, yeah, absolutely. A little bit more interesting than tomatoes and carrots.

Yeah, you're absolutely right. Eating, eating as widely as we can benefits our microbiome because you're feeding as many, you know, as many of your, you know, your onboard helpers as you can. Because if you think about it, say some pathogen comes in and it knocks out a particular. It knocks back or knocks out a particular kind of microbe or a particular community. Hey, well, there's no problem. You got 99 others that are going to fill in and help you out. If you're just the lettuce, tomato, carrot kind of person, you probably got far less in terms of diversity to fall back on should anything happen. It's just like that parallel in agriculture. Monocultures make you very, very vulnerable. A pest or pathogen can sweep through and boom, your crop is done. However, you know, if you've got a diverse operation, maybe you're running. You're running animals, not just a ruminant, but, you know, chickens as well. And you've got, you know, fruits and vegetables, but you've also got row crops. The same thing that takes out a chicken is not going to take out your corn, most likely. So you're always going to have something growing, you know, to eat or, you know, if you're a commercial farmer, you know, you'll always have something to sell. You know, that applies inside of our bodies, too.

Okay, got it, got it. So in terms of. And this is one of the last questions I want to ask you, but something that I think is really, really important that comes from your book that I'd love to hear you expound upon. You've studied plants and you've seen how plants extend roots into the soil. And there is this interplay not only in terms of the root collecting things from the soil, but also the root of the plant returning things to the soil. How is that parallel to the human body, like, to the gut? How is the gut like a root?

That was one of those sort of big aha moments in writing this book when we realized that essentially the root is the gut and vice versa, only inside out. We started to realize, oh, these interfaces, these boundaries between, like, the root and the soil and the colon and the inside of us are places where a diverse abundance of microbial life is actually working in tandem with the host. There's synergies that are happening there and symbioses. And, you know, you can sort of go right down the list where in the plant world the roots are Pushing out exudates into the soil to feed microbes. And in a person, the food that we eat is feeding our microbiome. But there's also. We didn't talk about, but we do go into it in the book. There's certain cells in the lining of the colon that produce mucus that some of the organisms in our colon are living off of. And when you go in and read the gastroenterology journals, they refer to them as exudates. So there's sort of parallels there. Those microbes that live in both areas in the rhizosphere around plant roots and inner colons are taking organic matter, and they're metabolizing it, they're consuming it, and they're making metabolites, their waste products that in the plant world, really benefit plant health, and in the human gut, really bolster our immune system and benefit our health. And so you basically have these connections that you can draw right on down the line, including there's chemical signaling that goes on between the plant or human host and their respective microbiome that helps inform their defense system, whether in a plant or our own immune system. So there's these parallel processes and services that are going on across those interfaces that really basically argue that the root is the gut inside out. And that illustrate why these long, evolutionarily honed partnerships between communities of microorganisms and the macroscopic hosts that define the world of nature. We know plants and animals are so important to the health of all the aspects of nature that we see around us. And a couple decades ago, this kind of thinking was kind of crazy talk. And now the science is coming to the point where it's really connecting the dots, and we can see how it works. And that parallel between the way root systems work and the human gut works for us really put this all in perspective, as this is a really big story about how nature actually works.

So would you say that in this case, where the gut would be like a root, what would represent the soil? Would it be the bloodstream?

Well, really, what represents the soil is that thick, nice, rich layer of mucus. It's very much like the soil on our Earth, where soil's a thin, thin little layer that is the difference between life and death. For things on our planet, Though thin, it is dynamic. It's got all of these things going on in it that we talked about in the rhizosphere and the exchange of metabolites. And so the colon lining itself is the analogy to the soil outside.

Okay. So it's a Mucosal lining. Gotcha.

But also figure there's a smattering of our own dietary materials on that colon lining. Right. So our microbes are living off of that as well.

Gotcha. Okay, makes sense. Makes perfect sense. So as far as your own diet and how that's changed as you've written this book, what would a sample day of eating look like for you guys? What would just like a breakfast, lunch, or dinner, some of the staple foods in your diet be based off of what you learned while writing this book or things that changed as you studied microbial diversity?

Yeah. Well, let's see. For breakfast, we're both big yogurt eaters. We both eat. We have different kinds. I like the yogurt at the farmer's market.

I was gonna say, is this like Dan and fruit at the bottom or that's.

This stuff's the biggest piece of junk. I like the yogurt at the farmer's market and Dave likes Nancy's yogurt. Both are full fat. The way I eat mine I put at this time of year, with no fresh fruit in season, I stock up over the summer and I freeze blueberries and raspberries. And so that's what we have for breakfast lunches. Right now our kale is kind of coming alive again in the garden. And it's just nice and tender. And so I'll often grab kale leaves and mix them with other greens, like with the lettuce. I've got some dandelion growing out there and I like to make a salad of like say maybe three or four different greens. I'll also right away, then we've got three different plant foods. And then I'll usually throw apple and walnut into salad. So now we're up to five plant foods. Maybe some olives if we have them, six plant foods. You know, you can see where that's going. And then for protein, I might throw a hard boiled egg into a salad. And that often is maybe a lunch or a dinner for us. And one of the things that, because a lot of people ask us this question, how'd you change your diet? And basically we eat more plant foods for lunches and dinners than we did in the past. And I have to say, we were never big junk food eaters, but we were not eating an abundance of fruits and vegetables. And so to sort of crack this nut again, if you go to our website, dig the number two, grow.com, there's a tab there, it's called make the plate. And on it there's illustrations and Recipe notes for how to do. It's mostly dinner type dishes, but it involves, you know, sometimes it involves say some kind of a grain like quinoa or a legume like a bean, and that becomes the base of a dish. And then different plant foods prepared in different ways piled on top of that base, and then some kind of yummy sauce that goes on top of it.

Cool.

Yeah. So like I say, there's one of the other things that changed for us is we started to explore a lot more the edible botanical world. You know, instead of just plain old white potatoes, there's actually, you know, several different kinds of orange fleshed potatoes. And those work, those are very tasty and work well in a lot of different dishes. And then, you know, you just take the world of beans alone, not to mention the other legumes, and you've got black beans, red beans, white beans, aduki beans, the speckled beans. And you see, why, to me, this makes sense from an evolutionary standpoint that we've always had more plant foods available to us to eat than we have animal foods. And our microbiome evolved that way as well. So that kind of gets back to the question of why is it important to eat a diversity of foods.

To me, I have sort of maybe a simpler view of changes in diets in the sense that I used to eat a lot more meat, cheese and bread than I do now. I still eat meat, cheese and bread because I love those three things. But my diet now has a lot more fiber rich plant foods in it and it's made a huge difference. So to me, it's sort of a change in the relative balance of what I was eating. A shift not so much in the components of my diet as in the relative proportions of them in what I'm eating. So it makes me think a lot more if I'm on the road, whether for geological work or book stuff, I think differently when I order off restaurant menus. We eat differently at home. And it's made a huge difference in the way I feel too.

Yeah. And I guess, Ben, nothing is truly off limits in our diet. It's more that we think in terms of this is what I'm, you know, this is what I'm eating today. And so if I'm like say, having a day where not enough, not enough vegetables and we're at a restaurant, it's like, well, I'm not going to order something that's full of meat. I'm probably going to get something, go more on the plant based way of things. And one of the, I'll just say one of the last things that we usually tell people is, you know, this is, you know, the book is packed with information from A to Z and you never think, oh, oh gosh, how are we going to get from the garden to the human colon? Well, you know, the journey that that took. So we usually tell people, hey, remember the fun factoids, the things that really appeal to you. But if nothing else, we leave people with these six words about diet and health and our planet and everything that we need to be healthy. And it's this. Mulch your soil inside and out.

Mulch your soil inside and out. I like it, I like it.

Yeah.

And mulch is basically a term that would kind of like be synonymous with composting, right?

Composting and plant. Just think plant world, right? Yeah, yeah, yeah. It's the mulch in the garden is really all the mulch in a garden is plant material and some restaurant. They're not going to get very far if they say, hey, we're putting mulch on your plate. But what you can tell them is, hey, I want some mulch on my plate.

Yeah, yeah, I like it, I like it. Well, your guys book is fascinating. And for people who are listening in, I will put a link to this book as well as to Dave and Anne's website over at BenGreenfieldFitness.com hiddenhalf that's BenGreenfieldFitness.com HiddenHalf and over there you can leave comments, you can leave questions, you can join the conversation. And I'd highly recommend that you go grab this book too. It's called the Hidden Half of Nature and I'll put a link to that as well. You can find it easily on a website like Amazon and it's well worth adding to your library. So check that book out. And Dave and Ann, I want to thank you guys for giving your time and for coming on the show today.

No worries. Thanks. It's been fun to talk to you.

Yeah, it's been super, Ben. Thank you.

Awesome. Well, folks, this is Ben Greenfield along with Dave and Anne, the authors of the Hidden Half of Nature, signing out from BenGreenfieldFitness.com have a healthy week. You've been listening to the Ben Greenfield Fitness podcast. Go to BenGreenfieldFitness.com for even more cutting edge fitness and performance advice.

Sam.