The Ruminant: Audio Candy for Farmers, Gardeners and Food Lovers - e.73: The Microbial Roots of Life and Health

Episode Date: February 26, 2016

In The Hidden Half of Nature, David R. Montgomery and Anne Biklé suggest we are in the midst of a scientific revolution of our understanding of the role that microbes play in the health of many other life forms on earth, including plants, as well as our own. I devoured this book, and for this episode, David, a geologist, and Anne, a biologist, are my guests. Also: the winner of The Salatin Semester giveaway is announced. You'll also hear a couple of ideas for replacing expensive specialty farm parts with their hardware store equivalents. The intro to this episode is kind of long. Skip ahead to, I don't know, 9 minutes to get to my conversation with Anne and David. 

And if you start looking at the root interface, think of it like a bizarre place where lots of trading goes on, where plants and microbes meet to trade their chemical wares to mutual benefit. Then you have a whole different way of looking at the life within the root zone of plants and what's going on below ground and how that actually helps support a flourishing diversity of life above ground. The Ruminant Podcast is for people who are passionate about farming, gardening, food politics, food security, and the intersections among these topics. At theruminant.ca, you'll find a summary of each episode, as well as book reviews, essays, and photo-based blog posts to stimulate your thinking about food production. I tweet at ruminantblog and email from editor at the ruminant.ca. All right, time for the

show. Hey folks, it's Jordan. So look, I have a terrific conversation lined up for you to listen to for this episode today, but first I got to get to some housekeeping. Last week, I announced that I have a free copy of Verge Permaculture's latest educational offering called the Salatin Semester to give away to one listener. I told you that if you wanted to be eligible, you needed to send me an email to tell me what you thought of the podcast or share a recent post from the Ruminants facebook page on your own facebook page or leave me a review on itunes well it turns out that a lot of you were really interested in the package or really want to find out more about joel salatin so i had a lot of responses and i just

want to say to those of you that wrote me emails i was really i was really touched by by some of the stuff i read um a lot of you really spent some time to write me an email to tell me what you think of the show. And there was some great feedback and some great suggestions. And I just really appreciate those words. Anyway, all of the names of all eligible listeners went into a hat and I pulled one. And the winner is Josh Baker of Rise Over Run Farm in British Columbia. Now, what I didn't tell Josh or any of you ahead of time is that there was actually a bit of a skill testing question portion to the contest. So I actually I have a clip of Josh going through that process.

Stop. Win the Salton semester. Must answer me these questions, Lee. The DVDs. PC. Ask me the questions. Ruminant Podcast. I am not afraid.

What is your name? My name is... Josh Baker. What is your quest? To seek the Salton Semester. What is your favorite color? Blue. Right, off you go.

Oh, thank you. Thank you very much. That's easy! All right, so Josh, congratulations. And I'll be in touch to give you your promo code to claim your prize. And everyone else, thanks again for your efforts to promote the show and write me emails and tell me what you think of the show and all the rest. I really appreciate it. And I'm sorry I didn't have a copy for all of you. But if you want to check out that package, it's at

SalatinSemester.com. Okay, so one more piece of housekeeping before we get to the main part of the episode. I recently had a voicemail left on my Skype number from a listener you've heard before. His name's Seth. He's at Amistad Farm. And, well, he wanted to share this. Hey, Jordan. It's Seth Stalling in Oklahoma. I just wanted to call, and now that I'm on the phone, my mind just blanked. But my friend Josh built a greenhouse, and he was noting, as I'm sure many do, that if you look for parts specifically made for greenhouses, it's, like, really expensive.

Often you can go and find something that does the same job that isn't specifically marketed for, but basically it's like a brush that goes on the inside or the outside of the roll-down sidewall and prevents air from coming in on the edges. So instead of buying the greenhouse part, he bought two different sized broom heads, you know, the long rectangle ones, and put those on the inside and outside. And they were like $10 each and served the exact same purpose as the greenhouse variety that costs triple that amount. So anyway, I stole that idea from him to share. But anyway, I would also love to hear a podcast on ideas like that, on things that maybe were built specifically for greenhouses that people found cheaper from other sources that weren't made specifically for that kind of purpose. Anyway, that's all. Thanks. Bye. Okay, so Seth, I really wish you hadn't blanked on the specific

piece of greenhouse equipment that you're talking about about because I tried to find what you're talking about online and I couldn't but I think we all get the idea and I think it's a good suggestion so I'm going to start us off okay so folks Seth is asking for things that can stand in for more expensive things that you use on your farm does that make sense it does to me and when I heard his message, I thought of something right away that I want to share with you. One thing I find, well, let's say two things that I find really expensive for the farm are any kind of like tomato trellising clips, as well as zip ties. And I make use of zip ties a lot around the farm, particularly in greenhouses when I'm, you know, holding things together, holding a ridge pole on the top of the hoop house or whatever. And in this case, I'm

talking about temporary hoop houses that come up and down every year. So I found a product at Home Depot that serves both purposes. It is called 7.5 inch 16 gauge rebar tie and it comes in a thousand pieces pieces per bundle and it is 10.95 canadian dollars these things are terrific uh you can use them to to trellis tomatoes to whatever your trellising is i would warn that the gauge of the wire is fairly thin so you need to leave plenty of room around the the stem of the tomato, which is really easy because you've got seven inches to deal with. If you go and look these things up, they've got these awesome little loops at the end of each tie. And it just makes it really quick and easy to quickly bend these things around to trellis plants. As for their function as zip ties, they also work really well.

You can just use it in place of a zip tie. And the nice thing is, um, so, so this wire really turns around itself really easily. You don't need pliers or anything. And the nice thing is you can then just undo it, uh, when you need to. Whereas with my zip ties, I'm often just, um, just cutting them and kind of treating them as a disposable. So yeah, I really recommend seven and a half inch 16 gauge rebar tie for actually serving all sorts of functions around the farm, but specifically tomato trellising and for in place of zip ties. So Seth, I think that's what you had in mind. Anyone out there got anything else they want to share? A cheaper hardware store

version of a tool or part specific for farming that is otherwise much more expensive, we'd love to hear it. Editor at theroomant.ca or yeah, just write me or record a voice memo and email that to me. Thanks, folks. All right, so on to the focus of today's episode. So a few months ago, I thought to myself, I wonder if David Montgomery has written anything new recently. David is the author of Dirt, Erosion of Civilizations, and that to myself, I wonder if David Montgomery has written anything new recently. David is the author of Dirt, Erosion of Civilizations, and that's a book I read, I don't know, five, six, seven years ago, and it's fantastic. It's all about humanity's abuse of its soil resources over, I guess, the millennia, and the effect that's had on various civilizations

that have come and gone, and what it may mean for our own civilization. Anyway, so just by chance, a few months ago, I looked up to see if David had written any books lately, and it turned out that within the last couple months before that, he had. He has just come out with a book co-written with his wife, Anne Biclay. David is a geologist, and Anne is a biologist, and they've written a book called The Hidden Half of Nature, The Microbial Roots of Life and Health. And folks, it was just an incredible read.

I was just so absorbed in this thing as I got into it. And as the title suggests, it's all about our emerging understanding of the role that the microbial world plays in plant health as well as in human health. And I think I can just I can leave it at that because we're going to get into it in the interview so um i've been really excited to share this with you i strongly recommend you pick up this book it is um really well researched really thorough and and for that reason it's thoroughness i recommend you read it because this interview just isn't going to cut it um but we had a great conversation and uh well i'm going to share that after a word from today's sponsor. Another public service announcement from Brill Cream.

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Brill cream, the gals will offer to ya. They'll up to get their fingers in your hair. Anne Biclay and David Montgomery, thanks a lot for joining me on the Ruminant Podcast. No worries. It's a pleasure to be here. Hello. Folks, you've written a book called The Hidden Half of Nature, The Microbial Roots of Life and Health.

And the very first line of the book in the introduction, well, I'll just provide this quote. We are living through a scientific revolution as illuminating as the discovery that the earth orbits the sun. That's quite an introductory sentence. And I'm wondering if you can expand on that. What are you specifically, what revolution are you referring to? Well, you know, you don't get to live through too many scientific revolutions. I'm a geologist. The last one that happened in my field was really the plate tectonics revolution that happened when I was a toddler. But if you look at the world of microbial science today, the way that we look at the

invisible or hidden half of nature, fungus, bacteria, archaea, that whole part of the world, our perception of it is truly being revolutionized by advances in technology and science over the past few decades. And in particular, by us realizing that there's far more microbes that are beneficial to plants, to animals, to people, than we had ever really appreciated. And there's a whole community ecology to the way these invisible organisms interact that really exert great influences over the parts of nature that we know and that Ann and I as a biologist and a geologist have studied for our professional lives. So we're really living through a change in how we perceive nature and our place in it. change in how we perceive nature and our place in it. The reason that it's taken us so long to make some of these new insights and for this revolution to get started is because of two paradigms that

have dominated the life sciences in the last few hundred years. And so I'm wondering if we can talk about those briefly. The first is the pathogen-obsessed or adversarial view of microbial life that we have taken in the life sciences in the last, I'll say, couple hundred years or more. Anne, can you break that down a little bit? Can you talk a bit about that pathogen-focused view of the microbial world? No, you're absolutely right, Jordan. It for a long time has been the dominant viewpoint. The way in which we've looked at the microbial world is that it's mostly, you know, all about diseases and sickness and illness. And there's a good reason for that, too. And that was because, you know, in the book, we described some of these early microbiologists. And in their day, they made some of the first discoveries that could link

a single microorganism with some kind of a malady or ailment. And they did this, you know, mostly with human diseases. And so, of course, when you're talking about, you know, hundreds of thousands, if not millions of people, you know, being killed by something like tuberculosis, that can tend to dominate your viewpoint. There's no doubt about it. And so that's what we call germ theory. And the theory is pretty simple. It's that you can trace a disease to a single microorganism. And that turned out to work really well in terms of identifying many of the major human diseases. And so it's a little like, you know, you make this pretty groundbreaking discovery in some kind of a field, and it completely colors how you look at everything about that field. So it was the start of medical microbiology that really sort of led to this blanket view that they're all sort of bad actors.

And it's kind of amazing that only here we are in 2015 and that it's only been maybe in the last decade or so that the microbiome field has started to really upend germ theory as the dominant paradigm for the microbial world. It's not to say that germ theory is bad or it doesn't work or anything, but it is to say that we've missed a good half of the story about the microbial world by only studying and investigating and appreciating them in their problematic forms. Okay, that's one of the two dominant paradigms of the life sciences that we've covered. The other comes from an aspect of evolutionary theory. You explain in the book that there's been a heavy emphasis on the role of competition

at the individual level in driving evolution, I suppose. We've largely ignored the role of symbiosis in driving evolution, or the role of symbiosis in ecology in general. Do I have that about right? Yeah, you know, that is right. And that was one of the things that was of great interest to me in researching this book, is to learn the history of thinking behind the ideas about how symbiosis played into evolution, and then learning about how solidly a lot of evidence now points to the rise of higher organisms, fungi, plants, animals, in terms of the mergers and symbioses of originally microbial organisms, but then also the way that communities of microbes developed partnerships with both plants and animals that played out over the long term, over geologic time, over evolutionary time,

in ways where you can really point to cooperation among species as having been a very big influence. And for many years, for almost a century and a half now, we've looked at evolution dominantly through the lens of natural selection and Darwinian competition, which are perfectly fine lenses to look at evolution through. There's a reason that that stuff works. But if you think about, in terms of our own lives, the way that a village of people has different kinds of specialists that cooperate to do different things that allow the ensemble living in that village to do more than if everyone was just living on their own individual homestead. communities of them can actually do things where the waste products from one provide the inputs or the food for another, and you can essentially develop systems in which different groups of microbes are actually benefiting one another.

And you can then take that to the next higher level and think about the way that microbes living around the roots of a plant or within the, say, the gut of a human can actually develop relationships with their host that are of mutual benefit. In the plant world, for example, the plants essentially exuding sugars into the soil that feed particular microbes that take that food, metabolize it and produce waste products or metabolites that the plant finds useful and then takes back up things as odd for a microbe to produce as plant growth promoting hormones. Why would a bacterium make a hormone to make plants grow better? Well, not just because they felt like it, but because if they did that, the plant then grows better, pumps more sugar into the soil, you can get more microbes.

It's a virtuous circle. And if you look back at the evolution of life on land, the very first fossils that we have of land plants have mycorrhizal fungi intimately associated with the roots. The whole process of life colonizing continents had a more cooperative effort or spin to pieces of it than we've traditionally looked at in thinking about evolutionary science. I like the village analogy, David, because if I could extend it a little bit, it's not

that those individual members of that village can't survive on their own, but that over time and working together, arguably know, arguably they can thrive, uh, in, in, in specializing and, and in, in forming relationships. Um, and that's exactly right. So folks, before we get into the meat of your book, like in, in more detail, I I'd like to talk about, you know, I guess the two catalyzing experiences that motivated you to write the book. I guess the two catalyzing experiences that motivated you to write the book. And I guess if I have the chronology right, the first, the first, the first experience was the experience of buying a new house and being very excited to,

to start a garden in that house and realizing you that the soil in your garden was, was very terrible. Do you want to talk about that? You know, we bought this house in North Seattle. One of the attractions of this house is it had a big lawn right next to the house that looked like it would someday make a good garden. Well, we forgot to do something very important that I'd actually done all around the world in my geological studies. We didn't dig a soil pit in the yard to actually look at, well, what was the quality of the soil, the dirt that we were buying along with this house?

When we, several years later, got to the point where we could start actually implementing Anne's garden plan, and we peeled that 100-year-old lawn off and found that there were no worms in the ground, there was almost no organic matter, it was basically not sterile, but pretty dead dirt. It was sort of a big surprise, like, oh, how can we actually turn this stuff into a garden? And Anne really took matters into her own hands by trying to restore the soil, to build soil on our lot by bringing organic matter in. She started bringing back leaves and adding coffee grounds and mulching the soil, putting wood chips on the soil, getting local arborists to drop chipped up

trees into our driveway so she could spread them on her planting beds. I watched this stuff go on for a couple of years and was actually busy writing a previous book that I did called Dirt, the Erosion of Civilizations, about how societies that did not take care of their soil ultimately failed when their soil gave out. And over the course of about five years or so, all of Ann's activity in bringing back organic matter in our yard really started to actually generate changes in the soil that we could notice. It was getting darker. It was getting browner, more richer.

Life came back to the yard pretty much in the order in which life evolved on Earth, starting with microbial life to then detritivores that would break up organic matter and arachnids, spiders, and millipedes, and then birds and mammals. We started realizing just what was going on in the yard and that she was running this experiment in reverse to what many societies had done to their soils throughout history. She was basically rebuilding soil far faster than nature could actually do it. The idea that that could happen so quickly was really a revelation to us.

Nature makes soil and builds fertility very slowly. You can build soil at rates of a fraction of a millimeter a year. And Anne had built several inches of fairly good soil in about half a decade. That's what really started us into looking into the plant side of this. That's what really started us into looking into the plant side of this. And where the book really took a major turn was when Ann had a major health issue that got us looking in terms of how do microbes relate to human health and the human immune system. And putting those two things together really ended up shaping the ultimate framing of the book. Right. So if you don't mind, Anne, maybe you could tell us a little bit about that.

You were at one point diagnosed with cancer and that kind of sent you on a journey to, I guess, learning, trying to learn as much as you could about your cancer. But ultimately, that led you to learn a whole bunch about, uh, I, I guess, ultimately the role of microbes in the body. Could you, could you talk about that a little bit? Yeah, yeah, sure. So, yeah, we'd been, we'd been, you know, going along both, um, in the garden with, And in the garden with restoring our soil, we were cruising along with the writing of this book. And about, you know, maybe halfway into it, I got a phone call that you never, ever want to get from your doctor. And I learned that I had cancer, and it was a malignant cancer, and caused, of all things, by a microbe, by a virus in particular, the human papillomavirus. And I had cervical cancer. I had a lot of questions like, where does our health come from, you know, in the first place? We had been aware of the microbiome, that's the name of this, you know, emerging and burgeoning field

of biology that is looking at indigenous microbes in the human world as well as, you know, the botanical world. But in my case, we were aware of it, but once we began to really look into it, it became pretty clear that these microbial communities, indigenous to our bodies, had a whole lot more to do with health than anybody had ever thought. If you look at sort of human history over the last, say, 100 years or so, a couple hundred years, let's say, most of the premature early deaths were due to some kind of infection. So for most of human history, that's what took us down,

were these very specific diseases caused by specific microorganisms. And then as we got clean water, sanitation improved, vaccines came online, antibiotics came online. So around now, we're around the Second World War. And so deaths greatly, greatly decreased from those causes. But then after the Second World War, as those deaths still kept declining, there were these other kinds of diseases that people seemed to be dying from earlier than they should have. And these are all the so-called chronic diseases. So these are things like type 1 diabetes or type 2 diabetes,

multiple sclerosis, various kinds of inflammatory disorders. And so as we looked into the microbiome, it looked like at the root of many of these chronic diseases from what researchers were writing about and studying, it seemed to be that a perturbed and altered microbiome lay at the root of some of these kinds of diseases. And so my questions about cancer, about how do you obtain health, how do you keep it, how do you get it back, was all leading it back. It was all leading in a direction

that was actually quite surprising to both of us. We never really realized until we got into it just how important the microbiome is for human health. At this point, I'd like to read another quote from the book. Resurgent agricultural pests, declining soil fertility, crisis level antibiotic resistance, and life-sapping chronic diseases all seem unrelated until you consider their roots in disrupted microbial ecology. And later in the book, you go on to talk about the striking similarities between plant roots and anac colons. And so now I'd like to delve into that at least a little bit. We'll talk about those similarities between plant roots and our colons a little later, but let's just start with plants. David, I'm just wondering if you could

talk a little bit about what's happening beneath the soil at the plant root and some of these relationships that plants have evolved with various microbes over the last millions, hundreds of millions, even, I guess, over a billion years. The thing that really put that in, the degree to which those kinds of adaptations between microbial communities living around the plant roots and the rhizosphere of the plants have shaped or that still shape plant health, the thing that drove that home for me was when I learned, well, when we learned in researching the book, that something like a quarter to a third of the carbohydrates, the sugars, the plants will photosynthesize, actually get pushed out the roots of the plants and into the soil. And, you know, when I first learned about this, I was thinking, you know,

what a crazy thing to do. This can't be very terribly efficient. You're just, like, putting all this energy into making these compounds, and then you're just basically pushing them out into the soil. It makes sense though when you think that plants would be doing that to feed microbes in the soil that then provide things in return for the plant and so this two-way exchange across plant roots i'd always thought of plant roots as stuff you know sucked up nutrients out of the soil that's what i was taught that's

you know what it makes sense we think of roots as straws that are drawing things out of the soil. That's what I was taught. That's what makes sense. We think of roots as straws that are drawing things out of the soil. I think that's what a lot of us assume. And I think you even write that early on when scientists realized that plants were putting compounds into the soil, there was even an assumption early on that they were just bleeding them out, like just they were leaking out almost. Isn't that true? Yeah, it was just inefficient, you know, kind of like if we just walked around town handing out money. Right. It would be a wonderfully altruistic thing to do, but people weren't really thinking that plants were altruistic. And so the initial thought was, you know, it's wasteful, it's inefficient. Well, it turns out that it's

actually hyper-efficient, because what plants have done by doing this is they've essentially outsourced the production of key compounds that facilitate their nutrition, their health, their growth. And if you look at, say, mycorrhizal fungi in the soil that develop intimate relationships with plant roots, some of them even burrow into the plant root itself and establish a direct physical connection between the fungus and the plant. And the mycorrhizal fungi can do something that plant roots can't really do themselves terribly well, and that is they can, they grow from incredibly long lengths and they can scavenge particular elements out of mineral soil, particularly phosphorus, although they can also get nitrogen

and a lot of the micronutrients that plants need. And they'll bring that material that they've highly selectively pulled out of rock fragments of mineral matter in the soil or out of weathering rocks below the soil as well. And they'll bring that into the rhizosphere, where it becomes then available to the plants. And the plants essentially pay off with sugars. Similarly, bacteria in the soil can help mineralize or mobilize things like phosphorus that's in the soil.

A lot of phosphorus that's loosely in the soil oxidizes and becomes very immobile very quickly. But bacteria can actually reprocess that and make it soluble again. And again, effectively, their metabolites can help nourish the plants. How do the plants make sure that there's the right kind and an abundance of those bacteria in the soil? By leaking out the right exudates, by pushing out the right exudates into the soil to essentially feed their microbial allies. It's a very different perspective through which to view the role of soil life as being absolutely critical to the growth, say, of healthy nutrient-dense crops and supporting the whole world of terrestrial life above ground.

world of terrestrial life above ground. Okay, so that's what that's, that's just a small sliver of what you folks learned when you researched what's happening within the botanical world. And I encourage people to read the book because your coverage of these topics is so comprehensive and fascinating, but, but we must move on. And so now I would, I'd like to talk about human health and what's happening in our bodies with regards to our relationship with the microbes. And I thought perhaps I'd start by asking, I guess I'll ask you, Anne, could you briefly explain the digestive system in terms of, you know, the three major components of the digestive system and what happens when we eat? Sure, yeah. Yeah, so most of us probably don't give a whole lot of thought about what happens to food after we chew it up and get all those great tastes and flavors out. And then it goes down the hatchet and we're, okay, well, it'll come out the other end at some point.

But there is a huge amount of things that happen between the top and the bottom. So the stomach is really a really acidic environment. And it is the acidity of somewhere around lemon juice or vinegar. And that will help to break down foods. And so there's nothing really in the way of absorption or sort of nutrient, getting the nutrients out of the food that goes on in the stomach. It's just sort of the first stop on the way to being broken down. And so food moves out of the stomach and it goes into the small intestine. And the food drops into the top of the small intestine and various digestive enzymes shoot into the small intestine at this point from the liver. And so fats and proteins and

carbohydrates start getting further broken down here in the small intestine. A simple carbohydrate, say a cookie, a Christmas cookie, say, that's got refined sugar in it. It's very short chains of sugars. They call them, you know, one to two carbons are in those molecules. So it's a small, simple molecule. It's really easy to break down. This is in contrast to, say, a complex carbohydrate. Say, you know, something that was in a fruit or a vegetable, you know, the skin of an apple or the pulp of a squash or something like that. And they're called complex carbohydrates because they are long, long, long chains of carbon strung together along with side chains of other molecules that might be attached, say some kind of a fat or some kind of a protein.

attached, say some kind of a fat or some kind of a protein. So what we talk about in the book is the difference between eating a simple sugar versus a complex sugar. And a simple sugar, because it's so quickly broken down, that nutrient, the sugar, it's absorbed pretty much right away in the small intestine. A complex carbohydrate, though, is not. It still is not really completely broken down. And... Hey folks, Jordan cutting in in post-production. I lost a few seconds of tape with Anne. There was some glitch with my recording, but what she's about to say is that when that complex carbohydrate reaches the lower intestine or the colon, we don't actually have the genes that code for the enzymes necessary to completely break down those complex carbohydrates. Okay, so back to Anne. Here we go.

But guess who does have the right genes that can make those enzymes? It's much of our microbiome that lives in the sort of bottom most part of the digestive tract called the colon. And the colon is synonymous with large intestine. But we just refer to it as the colon. And it's here that microbiome research is turning up a whole lot of really, really interesting things that go on in the colon. Your podcast is called The Ruminant,

and any farmer knows what goes on in a ruminant animal. And it turns out that we don't really have a rumen. The equivalent of what goes on in a rumen happens in our colon. And so that's where all of this bacterial breakdown of plant-based foods occurs. And so that's sort of the basic walk through the digestive tract. I will just go back to small intestine for a minute to say fats and proteins, because that's also in our food. They are primarily

broken down and absorbed in the small intestine. Unless that is, you're eating quite a bit of fat and quite a bit of protein. Some of that can sort of overwhelm the small intestine and it will land in the colon. And what's turning out to be pretty interesting is that the same microbes that can break down complex carbohydrates, they will also break down proteins and fats. But the key sort of difference is that the byproducts of protein digestion in particular in the colon produces some pretty nasty compounds, whereas the byproducts of complex carbohydrates in the colon turn out to be some pretty medicinal and beneficial compounds that are called short-chain fatty acids. And they are involved in, the short-chain fatty acids are involved in all kinds of things, both in the colon itself, and then it's also looking like systemically through our bodies. Another highly beneficial compound that is produced in our colon is serotonin. And serotonin is a neurotransmitter.

And it looks like the majority of it is produced not in our brain, which is what was once thought, but the majority is produced in our gut. And then it travels up to our brain. So, you know, there's, if you think about all of these, you know, various sayings that say, you know, go with your gut and so on, there's really a lot to that because of all of the things that are happening to our food as it passes through our digestive tract. So there in sort of a very large nutshell, Jordan, is the digestive tract. Well, thank you. And we can't possibly cover, I mean, it's just your coverage of what's happening in the body as we eat

and our relationship with microbes is extensive. We can't possibly cover it. I was really hoping to talk about chronic inflammation because essentially a lot of this portion of your book is about the ways in which we, through our diets and our behaviors and our own medicine, we abuse the microbes in our body. And so I think we should zero in on inflammation for at least a few minutes. If I could ask you to talk a little bit about what chronic inflammation is and what it stems from, and I guess touch on the very important relationship between microbes and our immune system.

So this is really, really quite interesting. People, you know, those in the medical field have known about inflammation for a really, really, really long time. And it has always been associated with, you know, dealing with some kind of infection. You get the soreness and the redness around a cut or a wound of some sort, and that's inflammation. What has in recent years become much more appreciated about inflammation is that it can also occur at a low level, at a level at which a person might not even be aware

that they have any inflammation going on in their body at all because there's no apparent symptoms or signs of that. But what it turns out is that these chronic low levels of inflammation, you mentioned chronic inflammation, that's just what it is, turn out not to be so good for the rest of our body. So how does it happen then that this chronic inflammation is plaguing us? And that takes going back down into that part of our digestive tract that we don't like to talk about, and it's probably the least loved part of our digestive tract that we don't like to talk about and it's probably the

least loved part of our whole digestive tract and that is the colon. Because as it turns out, about 80% of our immune system is wrapped around our digestive tract and of that, most of it is around the colon. If you picture your colon, your whole digestive tract really is really a tube. And if you take a cross-section through that, on the outside of the tube, that's where all of this immune tissue and immune cells are residing, and they're snugged up right against the colon wall. And your colon wall, get this, this is a little frightening to think about, but it's one cell thick, okay?

One cell. That's not a lot. And in part, you know, it is that way for a reason because we have all these immune cells on the outside of the wall and they need to know what's going on on the inside of the colon, know what's going on on the inside of the colon, in part because it's a great way for our immune system to detect, say, any bad microorganisms that have come in through food or water that we might have ingested. But the microbiome research is also telling us that there are beneficial microbes, our indigenous microbes, that live not out sort of in the center of the colon, but very, very close to the colon wall in this thick layer of mucus that coats our colon.

So you have immune cells that actually can, one in particular called a dendritic cell, it can put sort of an amoeba-like arm in between two colon cells, and it's going on a fishing expedition into the colon to see what's there, both to see if there's anything bad that was in our food or water, but also it's communicating with these indigenous microbes that live in our mucus. And in experiments on mice and then indirect evidence in people is showing that our immune cells are picking up chemical signals from these indigenous microbes that live in our mucus. And these signals are sort of, you might say,

they're teaching and toning our immune cell for which kind of microbes are friendly and which kind are dangerous. And this is a whole new way of looking at immunity and looking at the way that our immune system operates. Because there's the standard traditional notion that is true, that is our immune system is on the lookout for pathogens and bad actors, and it's going to find those and kill them. And it does do those things. But this other aspect of the immune system, just as important, is that it be communicating effectively with these indigenous microbes that are in the colonic mucus. And so what you want to have is you want to have the full complement of microbes that live in that mucus because they've got the full complement of all of this chemical signaling,

much like what occurs in the rhizosphere of a root, right? You want to have the right kinds and the right combinations because then they're communicating effectively with the immune system. And when they're not, say some microbes are missing, or I talked earlier about a perturbed or altered microbiome, when they're missing, the chemical signals and signaling isn't happening, When they're missing, the chemical signals and signaling isn't happening. And the immune system, the human immune system is designed to take care of us.

And I would say on the whole, if there's any question, you know, in the part of our immune system or immune cells about whether something is friendly or might be potentially harmful, it's going to err on the side of, hmm, I don't recognize this thing. It's probably harmful. I'm going to attack it. And so that's what chronic inflammation is. It's this very low level of sort of disordered communication between our immune system and various microbes that should be teaching and instructing it. And this isn't to say, and we need to remind ourselves too,

it's not all microbiome alterations that are at the root of everything. Our bodies and biology are very complex. For certain autoimmune conditions, there's a genetic component. But when you add the genetic component in with the altered microbiome, then that's the recipe that you get. It might not be one or the other. It takes two for some of these things to manifest. So David, as an organic farmer, I spend a lot of time reading about the crucial role of organic matter in soil fertility and soil health. But it's really interesting because I find that, I mean, I also spend a lot of time looking at proper soil chemistry and soil physics. the only farmer who finds it way easier to to um understand the soil chemistry and soil physics and and to understand you know the effect of this or that amendment that i'm putting on my soil i guess i guess the way i would put it is i i almost have to put faith in a lot of the principles

i read about um with regards to to soil biology i guess partly because you you it's it's it's so hard to imagine what's going on beneath the soil and these complex relationships. And that's why I took note when in your book, one of you anyway, wrote that along the way you went from being cynical echo pessimists to cautious echo optimists. And I imagine that took place as you did more and more research. And I'm just wondering, what did you mean by that? Like, how cynical were you when you started out? Well, you know, if you look back at the history of how societies have taken care of their

land, it's pretty easy to be pretty cynical about our chances this time around in the way that we've been abusing soil globally for a century and a half now. But what really sort of turned me around in terms of thinking about whether we could pull out a real major agricultural reform that could save us from repeating ancient mistakes this time at a global level was seeing how fast soil could be restored when you do start paying attention to some of those simple principles. And you can boil them down kind of to the simple principles of what's loosely called conservation agriculture,

in terms of don't disturb the soil surface, don't plow, and bring in cover crops that include legumes in a complex rotation, is the third principle. And those could apply both to organic and more conventional-ish agriculture. principle. And those could apply both to organic and more conventional-ish agriculture. But those are ways that really seem to foster the beneficial effects of soil life. And you're right that using those principles almost involves a leap of faith because you can't see microbial life. It's one of the big problems we've had in trying to study it and understand it is that how do you understand the interactions of organisms and communities that you can't even see

with with the senses that were born with that you need technology to even be aware of their existence and this is one of the big problems that people like Sir Albert Howard one of the pioneers of organic agriculture, faced back in the 1930s when he came up with large-scale composting methods that could work in the tropics. He promoted not disturbing mycorrhizal fungi in the soil. He came up with some of the very basic ideas and principles that still underlie organic agriculture. And the scientific community didn't really buy into what he was doing because he didn't really have a mechanism to offer.

He was basically asking people to take it on faith because he saw these processes work on his farm and on large plantations. And so he developed concepts around why they worked, but he couldn't actually connect the dots in terms of a mechanism. In essence, I was trying to figure out the mechanisms, but through which how things work. What this sort of new perspective on microbial life and microbial community ecology has really done, in a surprising way, is offer some of the mechanisms for the processes and connections that people like Sir Albert Howard were arguing for and recognizing

back when they didn't have the tools to actually understand how you actually connect the dots. So it's, you know, in terms of our own senses, there is sort of an element of faith that one's doing the right thing in terms of that kind of a world. One can run the experiment at a large scale and see whether it actually works. But what the modern microbiome science in the plant world is starting to provide is an understanding of really sort of how it works, how those mechanisms connect, that those dots actually really do connect, and that there's this other dimension in terms of managing soil to promote fertility and productivity, which involves learning about how to actually deal with the care and feeding, the stewardship,

the cultivation of the beneficial microbes in the soil, which gives us a whole different set of tools to think about, a different set of principles to frame our practices through. Well, folks, it was just such an engrossing read. And I think the best compliment I can pay you is that I haven't been able to eat in the same way since I read it. And I mean that in a very good way. I have a terrible sweet tooth, but I have not shown such discipline ever or in years and years like I've shown in the last few weeks since I first read the book.

And I'm really – you've taught me a lot. I'm really optimistic. I'm now reading – I'm looking for other books to read on this stuff because, I mean, we talk about a scientific revolution. You have at least started a revolution in my own thinking. And we really only scratched the surface today. I mean, we talk about a scientific revolution. You have at least started a revolution in my own thinking. And we really only scratched the surface today. And I just strongly suggest that my listeners check out this book. It's a very, very good book.

And I just want to thank you so much for joining me on the podcast today. Well, thank you much. Appreciate it. Enjoyed talking to you. Yeah, Jordan. And for you and your listeners, we also have the Hidden Half of Nature also has a website. And our website is Dig2Grow, and that's D-I-G and then the number two and then the word grow, dig2grow.com. And we're on Facebook as the Hidden Half of Nature.

We're on Facebook as The Hidden Half of Nature, and we are on Twitter. Our handle is atdig2grow, spelled just like the website. So there's far more there in those places for you or others to follow. In fact, I'll just say here, since you mentioned eating, we recently put a new page up on the website called Make the Plate. Because there's the one illustration in the book that talks about, you know, well, how do you feed your microbiome? What does a microbiome-friendly diet look like? So there's some pictures on the website for folks who are more visually oriented,

There's some pictures on the website for folks who are more visually oriented, and along with, you know, kind of recipe-type instructions for how to make those things. Well, yeah, I'll check it out myself, and I hope my listeners will do the same. Thanks again, folks. Okay. Great, thank you. Thank you, Jordan. So that's it, folks.

I hope you enjoyed that. So listen, before I cut out right now, I just want to talk about the new format that we're kind of in the midst of unfurling on the Remnant Podcast. The way it's going to work is one week, we're going to have a long form interview, usually on a more broad topic or a bigger idea for agriculture, food, farming, that sort of thing.

And then the next week, we're going to zoom in and focus on a few practical skills for farmers of different disciplines. So it's already technically happened. Last week was kind of the first focus on practical skills. This week was a broader conversation with these two authors. And then next week is going to be zooming in again

and focusing on some practical skills. So I'm really excited for the new format. I think you're going to like it. You can always email me, editor at theruminant.ca, and tell me what you think. But that's kind of what's to come. Now, I have talked over Vanessa's song a little more than usual, and I know a lot of you like it,

so I'll just take that chance to remind you that if you go to theruminant.ca slash podcast, you can stream or download a copy of this outro song by my wife Vanessa. So feel free to go do that and have a great week. Thanks again for all your participation in last week's contest and I'll talk to you soon. Would we live in a place that don't want us?

A place that is trying to bleed us dry? We could be happy with life in the country With salt on our skin and the dirt on our hands I've been doing a lot of thinking, some real soul searching, and here's my final resolve. I don't need a big old house or some fancy car to keep my love going strong. So we'll run right out into the wilds and braces We'll keep close quarters with gentle faces And live next door to the birds and the bees And live life like it was meant to be Bye.