Latest / The Last Observer: Science and Beyond / You're Not One Organism—You're an Entire Ecosystem

Transcript

You're Not One Organism—You're an Entire Ecosystem · The Last Observer: Science and Beyond

• 0:00
  Speaker 1: You know, usually when we talk about human biology or
• 0:03
  Speaker 1: health or even psychology, there's this massive underlying assumption, right.
• 0:09
  Speaker 2: The expectation of absolute individuality.
• 0:11
  Speaker 1: Exactly, you think of yourself as this, you know, single cohesive,
• 0:15
  Speaker 1: self contained unit. You wake up, you walk into the bathroom,
• 0:18
  Speaker 1: you look in the mirror, and you see one person
• 0:20
  Speaker 1: staring back.
• 0:21
  Speaker 2: Yeah, it's a very clean narrative.
• 0:23
  Speaker 1: It really is. You see your eyes, your skin, your hair,
• 0:26
  Speaker 1: and it's comforting. Honestly, you are unequivocally you.
• 0:29
  Speaker 2: It is entirely comforting. I mean, it's a very singular,
• 0:32
  Speaker 2: isolated perspective of existence that we've relied on for centuries. Right,
• 0:36
  Speaker 2: it makes total sense on a macroscopic level.
• 0:39
  Speaker 1: But then you step into the world of modern microbiology,
• 0:42
  Speaker 1: into the reality of cellular ecosystems, and suddenly that mirror
• 0:45
  Speaker 1: just completely shatters.
• 0:46
  Speaker 2: Oh, it breaks into a billion pieces.
• 0:48
  Speaker 1: Right, we are looking at a biological landscape that dismantles
• 0:51
  Speaker 1: basically everything we thought we understood about who, or rather
• 0:56
  Speaker 1: what we actually are.
• 0:58
  Speaker 2: It is the absolute definition of paradigm shift. Biologically speaking,
• 1:02
  Speaker 2: that individual you see in the mirror it is a complete.
• 1:05
  Speaker 1: Illusion, a complete illusion.
• 1:07
  Speaker 2: Yes, you are not a single organism. You are a
• 1:09
  Speaker 2: super organism. To put it accurately, you are a bustling, walking,
• 1:14
  Speaker 2: breathing planet.
• 1:15
  Speaker 1: Okay, I want to get right into the scale of this,
• 1:18
  Speaker 1: because the numbers we are dealing with here are so
• 1:21
  Speaker 1: staggering they almost sound like science fiction.
• 1:24
  Speaker 2: They really do.
• 1:25
  Speaker 1: We aren't just talking about, you know, a few bacteria
• 1:27
  Speaker 1: hanging out on our skin or a little bit of
• 1:29
  Speaker 1: plaque on our teeth. We are talking about roughly thirty
• 1:32
  Speaker 1: eight trillion micro organisms living in and on you right
• 1:36
  Speaker 1: this second.
• 1:37
  Speaker 2: Thirty eight trillion. And it's not a monoculture either. It's
• 1:41
  Speaker 2: a wildly diverse rainforest of bacteria, fungi, viruses, and arcaia.
• 1:46
  Speaker 1: I have to pause you right there, because I know
• 1:48
  Speaker 1: what bacteria are, I know viruses, I know fungi, But
• 1:51
  Speaker 1: what on earth is an archaia?
• 1:53
  Speaker 2: That is such a great question because they usually just
• 1:55
  Speaker 2: get left out of the conversation completely. Arkia. Are these
• 1:58
  Speaker 2: fascinating single celled organs?
• 2:00
  Speaker 1: Are they just a type of bacteria?
• 2:02
  Speaker 2: Well, if you looked at them under a basic microscope,
• 2:04
  Speaker 2: you might mistake them for bacteria, But genetically and biochemically
• 2:09
  Speaker 2: they are an entirely different domain of life. They are
• 2:12
  Speaker 2: actually famous in the scientific community for being extremophiles.
• 2:16
  Speaker 1: Extremophiles like things that live in volcanos exactly.
• 2:20
  Speaker 2: They are the organisms you find thriving in boiling acid
• 2:23
  Speaker 2: springs in yellowstone, or like in the crushing pressure of
• 2:27
  Speaker 2: deep sea hydrothermal vents, where literally no other life can survive.
• 2:32
  Speaker 2: But as it turns out, a very specific subset of
• 2:35
  Speaker 2: them decided that the human gut was a perfectly cozy,
• 2:38
  Speaker 2: oxygen free extreme environment to just set up shop.
• 2:42
  Speaker 1: So I literally have yellowstone extremophiles living in my intestines
• 2:45
  Speaker 1: right now.
• 2:45
  Speaker 2: You do, specifically a type called methanogens. They take the
• 2:49
  Speaker 2: byproducts created by your bacteria and convert them into methane gas.
• 2:53
  Speaker 1: That is wild, it is.
• 2:54
  Speaker 2: But bringing it back to that here scale thirty eight
• 2:57
  Speaker 2: trillion of these various microds. To put them into perspective,
• 2:59
  Speaker 2: the human body is made up of about thirty trillion
• 3:02
  Speaker 2: human cells.
• 3:03
  Speaker 1: Oka. Wait, so if we are just doing a basic
• 3:05
  Speaker 1: head count.
• 3:05
  Speaker 2: By cell count alone, you are essentially a fifty to
• 3:08
  Speaker 2: fifty split half human half microbe.
• 3:11
  Speaker 1: You are literally as much them as you are you. Yeah.
• 3:14
  Speaker 2: Well, historically scientists actually thought the ratio was ten to
• 3:18
  Speaker 2: one in favor of microbes. That was this widely quoted
• 3:21
  Speaker 2: statistic for decades. Oh really, yeah, it wasn't until a
• 3:25
  Speaker 2: major study in twenty sixteen meticulously recounted and corrected the
• 3:29
  Speaker 2: math that we arrived at this one point three to
• 3:32
  Speaker 2: one ratio, which is roughly fifty to fifty. But you know,
• 3:35
  Speaker 2: the cell count isn't actually the most important part of this.
• 3:38
  Speaker 1: Story, right, because here's where it gets incredibly humbling. It's
• 3:41
  Speaker 1: not just the physical head count. It's the genetic mismatch.
• 3:44
  Speaker 2: Yes, what's truly profound is when you look at the
• 3:47
  Speaker 2: genetic blueprint, the human genome, the DNA that makes you
• 3:50
  Speaker 2: a human being, the instructions for your eyes, your heart,
• 3:53
  Speaker 2: your brain.
• 3:53
  Speaker 1: It contains roughly twenty thousand protein coding genes, which you know,
• 3:59
  Speaker 1: sounds like a lot until you compare it to our passengers.
• 4:01
  Speaker 2: Exactly, because the collective genome of all these microbial inhabitants,
• 4:05
  Speaker 2: the microbiome, it contains over two million unique genes.
• 4:10
  Speaker 1: Two million. Let's break down why that matters. Because a
• 4:13
  Speaker 1: gene isn't just like a piece of trivia. Gene is
• 4:16
  Speaker 1: an instruction manual.
• 4:17
  Speaker 2: Right Exactly. A gene is a recipe for a protein
• 4:20
  Speaker 2: and proteins are the tools, the enzymes, the structural building
• 4:24
  Speaker 2: blocks that do the actual work of keeping a living
• 4:27
  Speaker 2: thing alive.
• 4:28
  Speaker 1: Okay, so if you only have twenty thousand tools in
• 4:31
  Speaker 1: your human.
• 4:31
  Speaker 2: Toolkit, but your microbes have a toolkit of two million, right,
• 4:35
  Speaker 2: functionally speaking, they have a vastly superior capacity to perform
• 4:39
  Speaker 2: biochemical tasks. Genetically, we are outnumbered one hundred to one.
• 4:43
  Speaker 2: You are one percent human and ninety nine percent microbe.
• 4:46
  Speaker 1: Which fundamentally changes how we have to view the human body.
• 4:49
  Speaker 1: I mean, this complex collection of microscopic life doesn't just
• 4:53
  Speaker 1: live on you like a bunch of random hitchhikers waiting
• 4:56
  Speaker 1: for a ride.
• 4:56
  Speaker 2: No, they aren't squatters. They co evolved with us over
• 4:59
  Speaker 2: millions years. This ecosystem actually works as an invisible, vital.
• 5:04
  Speaker 1: Organ and we have to treat it like an organ.
• 5:06
  Speaker 2: Just like your heart pumps blood and your lungs exchange oxygen,
• 5:10
  Speaker 2: your microbiome performs specific, non negotiable physiological functions. It heavily
• 5:16
  Speaker 2: directs digestion, it trains the immune system, and it even
• 5:20
  Speaker 2: directly influences brain chemistry.
• 5:22
  Speaker 1: Think of the human body like a massive global corporation.
• 5:25
  Speaker 2: Okay, I like that.
• 5:26
  Speaker 1: You look at the building, it has your name on it.
• 5:28
  Speaker 1: You sit in the corner office. You think you are
• 5:31
  Speaker 1: the CEO, right, You're calling all the shots exactly, But
• 5:34
  Speaker 1: the reality is ninety nine percent of the actual day
• 5:37
  Speaker 1: to day work. The IT department, the manufacturing floor, the
• 5:41
  Speaker 1: security t in the front door, the cafeteria, all of
• 5:43
  Speaker 1: that is being outsourced to an army of independent contractors.
• 5:48
  Speaker 1: You might be the CEO, but without those contractors, the
• 5:51
  Speaker 1: entire company goes bankrupt by Tuesday.
• 5:54
  Speaker 2: That is a brilliant way to conceptualize it. We provide
• 5:57
  Speaker 2: the office space, the physical structure, the controlled temperature, but
• 6:01
  Speaker 2: they are the ones actually keeping the operations running.
• 6:03
  Speaker 1: So, if we're outsourcing so much of our bodily function
• 6:08
  Speaker 1: to these trillions of microscopic independent contractors, how exactly is
• 6:13
  Speaker 1: this partnership playing out? Like, if I'm the CEO, I
• 6:16
  Speaker 1: want to see the productivity report. Fair enough, Let's start
• 6:19
  Speaker 1: with the most fundamental need of any living thing, which
• 6:21
  Speaker 1: is fuel, metabolism, and digestion. If these microbes have two
• 6:26
  Speaker 1: million genetic tools, how are they using them when I
• 6:29
  Speaker 1: eat dinner?
• 6:30
  Speaker 2: Well, if we connect this to the bigger picture of
• 6:33
  Speaker 2: human evolution. There's a fascinating paradox. Humans are omnivores. We
• 6:37
  Speaker 2: pride ourselves on being able to eat almost anything on
• 6:39
  Speaker 2: the planet, right, But the truth is our own human
• 6:42
  Speaker 2: enzymes are native biological scissors used for cutting up food
• 6:45
  Speaker 2: into usable energy. They're actually remarkably limited.
• 6:47
  Speaker 1: Let's clarify that. What can we actually digest on our own.
• 6:50
  Speaker 2: Our internal chemistry set is pretty basic. We can break
• 6:53
  Speaker 2: down simple carbohydrates like a piece of white bread or
• 6:56
  Speaker 2: the sugar in an apple. We can break down proteins
• 6:59
  Speaker 2: from meat or and we can break down fats. Your
• 7:02
  Speaker 2: stomach acid and the digestive enzymes produced by your pancreas
• 7:05
  Speaker 2: and small intestine. They handle those macronutrients quite easily.
• 7:09
  Speaker 1: Okay, so a steak in a potato my human body
• 7:12
  Speaker 1: can handle just fine.
• 7:13
  Speaker 2: Yes, but that is exactly where your native toolkit ends.
• 7:17
  Speaker 2: When you eat complex plant fibers, the kind you find
• 7:20
  Speaker 2: in vegetables, lagoons, seeds, whole grains, yeah, your human body
• 7:25
  Speaker 2: actually has absolutely no idea what to do with them.
• 7:27
  Speaker 1: Wait, I need to stop you there. I eat a
• 7:29
  Speaker 1: kale salad or a huge bowl of lentils, which literally
• 7:32
  Speaker 1: everyone says, is the healthiest thing you can put in
• 7:34
  Speaker 1: your body.
• 7:35
  Speaker 2: Yes, they do.
• 7:36
  Speaker 1: Are you telling me that my human cells don't actually
• 7:38
  Speaker 1: know how to digest it?
• 7:40
  Speaker 2: Not directly. No, And to understand why, you have to
• 7:43
  Speaker 2: look at the chemical structure of plants. Plants need to
• 7:46
  Speaker 2: stand up against gravity. They don't have skeletons, obviously, so
• 7:49
  Speaker 2: they build incredibly strong cell walls using complex carbohydrates like cellulose.
• 7:55
  Speaker 2: The sugars and cellulose are linked together by something called
• 7:57
  Speaker 2: a beta glycosidic.
• 7:59
  Speaker 1: Bond, the beta ball right.
• 8:02
  Speaker 2: Think of it like a puzzle piece. Human digestive enzymes
• 8:05
  Speaker 2: are shaped to break apart alpha bonds, which are found
• 8:07
  Speaker 2: in starches like potatoes. Snip, snip, snip, and you absorb
• 8:11
  Speaker 2: the sugar.
• 8:11
  Speaker 1: Simple enough.
• 8:13
  Speaker 2: But our enzymes simply do not fit the chemical angle
• 8:16
  Speaker 2: of a beta bond. We just don't have the scissors
• 8:18
  Speaker 2: for it.
• 8:18
  Speaker 1: Wow.
• 8:19
  Speaker 2: So those complex plant fibers pass through your stomach and
• 8:22
  Speaker 2: travel the entire length of your small intestine, completely untouched.
• 8:26
  Speaker 2: From your human cell's perspective, that material is entirely indigestible.
• 8:31
  Speaker 1: That is mind blowing. So if it were entirely up
• 8:34
  Speaker 1: to my human genetics, I would extract zero energy from
• 8:37
  Speaker 1: that plant fiber. I would essentially starve to death on
• 8:40
  Speaker 1: a giant pile of raw.
• 8:41
  Speaker 2: Brockly you would your human digestive enzymes. Just watch it
• 8:44
  Speaker 2: float by. But thankfully it doesn't just pass straight through
• 8:48
  Speaker 2: and exit the body. It travels down the line until
• 8:50
  Speaker 2: it reaches the large intestine, the colon, and this is
• 8:53
  Speaker 2: where the magic happens.
• 8:54
  Speaker 1: The byreactor.
• 8:55
  Speaker 2: Yes, this is the biological bioreact.
• 8:57
  Speaker 1: So the colon isn't just a waste shoot.
• 8:59
  Speaker 2: Oh not at all. The large intestine is the most
• 9:01
  Speaker 2: densely populated microbial habitat on planet Earth. It is dark,
• 9:07
  Speaker 2: it is completely devoid of oxygen, and it is packed
• 9:09
  Speaker 2: with bacteria that possess the millions of specialized genes required
• 9:13
  Speaker 2: to break down those tough beta bonds.
• 9:15
  Speaker 1: So this is where your contractors take over.
• 9:17
  Speaker 2: Exactly. They ferment the fiber.
• 9:18
  Speaker 1: Okay, when I hear fermentation, I think of brewing beer
• 9:21
  Speaker 1: or making sour dough bread. What does fermentation look like
• 9:25
  Speaker 1: inside the human colon?
• 9:27
  Speaker 2: It's a very similar biochemical process. Actually, the bacteria consume
• 9:31
  Speaker 2: the plant fiber that you couldn't digest, and through a
• 9:34
  Speaker 2: complex series of metabolic reactions. They turn that raw material
• 9:38
  Speaker 2: into a class of molecules called short chain fatty acids
• 9:41
  Speaker 2: or SCFAs.
• 9:42
  Speaker 1: Short chain fatty acids. What do those do well?
• 9:44
  Speaker 2: There are three main ones, acetate, proponate, and most importantly,
• 9:48
  Speaker 2: buty butrate.
• 9:49
  Speaker 1: Okay, whenever I dig into the science of longevity or
• 9:51
  Speaker 1: gut health, butyrate just keeps popping up everywhere. But what
• 9:55
  Speaker 1: is it actually doing.
• 9:57
  Speaker 2: What's fascinating here is how vital buttery is to your
• 10:00
  Speaker 2: moment to moment survival. You see, most cells in your body,
• 10:04
  Speaker 2: your brain cells, your muscle cells, they rely on glucose
• 10:07
  Speaker 2: blood sugar for energy. But the cells that physically line
• 10:11
  Speaker 2: the walls of your colon known as kolanocytes, they don't
• 10:14
  Speaker 2: want glucose. They actually prefer and require buterate to fuel
• 10:18
  Speaker 2: their mitochondria. It provides about seventy percent of their energy
• 10:22
  Speaker 2: needs and is wild.
• 10:24
  Speaker 1: The human cells making up the walls of my own
• 10:26
  Speaker 1: organs are relying on the exhaust fumes of bacteria just
• 10:29
  Speaker 1: to stay alive exactly.
• 10:31
  Speaker 2: And it gets more intense than that if those colon
• 10:34
  Speaker 2: cells do not get enough buterate, meaning if you don't
• 10:36
  Speaker 2: feed your bacteria enough plant fiber, what happens, those human
• 10:40
  Speaker 2: cells will begin to undergo autophagy. They will literally start
• 10:42
  Speaker 2: eating themselves to survive, and eventually they die.
• 10:45
  Speaker 1: And if the cells lining my colon dye, I assume
• 10:47
  Speaker 1: the wall just breaks down.
• 10:49
  Speaker 2: Precisely, butyrate keeps those colon cells healthy, plump, and energized.
• 10:54
  Speaker 2: By doing so, it keeps the gut wall structurally sound.
• 10:57
  Speaker 2: It maintains a tight barrier preventing unwanted talks from leaking
• 11:00
  Speaker 2: out of the digestive tract and into your bloodstream.
• 11:03
  Speaker 1: Oh wow, we'll get into that more when we talk
• 11:05
  Speaker 1: about the immune system. But the structural integrity of your
• 11:08
  Speaker 1: gut relies entirely on microbes turning fiber into butyrate.
• 11:12
  Speaker 2: Okay, so they are our energy producers, but their manufacturing
• 11:17
  Speaker 2: skills don't stop at just fuel, right. They're also acting
• 11:20
  Speaker 2: like an internal pharmacy.
• 11:21
  Speaker 1: They are Certain bacteria like Biffidobacterium, actually manufacture essential vitamins
• 11:27
  Speaker 1: that we struggle or completely fail to produce ourselves.
• 11:31
  Speaker 2: Which vitamins are we talking about here?
• 11:33
  Speaker 1: We're talking about vitamin K, specifically vitamin K two, which
• 11:37
  Speaker 1: is absolutely essential for blood clotting and bone health. Without it,
• 11:42
  Speaker 1: you would bleed out from a minor scrape.
• 11:44
  Speaker 2: Jesus.
• 11:44
  Speaker 1: Yeah, they also synthesize a whole suite of vital B
• 11:47
  Speaker 1: vitamins B twelve, folate, biotin, riboflavin. These are highly complex
• 11:52
  Speaker 1: molecules that require multiple enzymatic steps to assemble. The bacteria
• 11:56
  Speaker 1: literally do the assembly line work, and then share the
• 11:58
  Speaker 1: final product with us. Okay, if this raises a massive
• 12:01
  Speaker 1: realization for me, when I sit down to eat, I'm
• 12:04
  Speaker 1: not really eating to feed myself. I'm essentially just tossing
• 12:07
  Speaker 1: raw materials down into the basement from my microbial contractors,
• 12:11
  Speaker 1: and then I'm living off the chemicals they manufacture.
• 12:13
  Speaker 2: In many profound ways. Yes, you are feeding the ecosystem,
• 12:17
  Speaker 2: and the ecosystem is feeding you.
• 12:19
  Speaker 1: But I have to ask the skeptics question here, why
• 12:22
  Speaker 1: did we evolve this way? I mean, if vitamin K
• 12:25
  Speaker 1: is so essential, and if extracting energy from plants is
• 12:28
  Speaker 1: so important, why didn't humans just evolve the genetic tools
• 12:31
  Speaker 1: to do it ourselves. Why rely on this massive foreign army.
• 12:34
  Speaker 1: It seems I don't.
• 12:35
  Speaker 2: Know, risky, It does seem risky, But if we look
• 12:37
  Speaker 2: at the evolutionary brilliance of this arrangement, it actually makes
• 12:40
  Speaker 2: perfect mathematical sense regarding energy conservation. This ties into something
• 12:44
  Speaker 2: called the expensive tissue hypothesis.
• 12:46
  Speaker 1: Okay, what is that?
• 12:47
  Speaker 2: Biological tissue is metabolically expensive to maintain. It takes a
• 12:51
  Speaker 2: lot of calories just to keep oregans functioning. Now, breaking
• 12:54
  Speaker 2: down tough fibrous plant matter natively requires a massive, multi
• 12:58
  Speaker 2: chambered stomach, incredibly long digestive tracks, and just countless specialized enzymes.
• 13:04
  Speaker 2: Think about a cow. A cow spends its entire day
• 13:08
  Speaker 2: chewing cut fermenting grass in its room, and constantly dedicating
• 13:12
  Speaker 2: energy to digestion.
• 13:13
  Speaker 1: Right. A cow has a huge belly and essentially just
• 13:16
  Speaker 1: eats and digests all day long.
• 13:18
  Speaker 2: Exactly. But early hominids made a different evolutionary bet. By
• 13:23
  Speaker 2: outsourcing the heavy, metabolically exhausting lifting of digestion to microbes,
• 13:28
  Speaker 2: human bodies were able to shrink our digestive tracts significantly.
• 13:32
  Speaker 2: We saved an enormous amount of metabolic energy.
• 13:35
  Speaker 1: Yeah, what did we do with all that saved energy?
• 13:37
  Speaker 2: We diverted it up. We use that saved energy to
• 13:39
  Speaker 2: evolve a massive, incredibly complex, energy hungry brain. Your brain
• 13:44
  Speaker 2: is only about two percent of your body weight, but
• 13:46
  Speaker 2: it consumes twenty percent of your energy. Oh wow, Yeah,
• 13:49
  Speaker 2: we could never have fueled this brain if we had
• 13:51
  Speaker 2: to dedicate all our energy to digesting raw plants. So
• 13:55
  Speaker 2: we provide the warm, safe habitat and a steady delivery
• 13:57
  Speaker 2: of raw materials. The microbes cook the actual meal, extract
• 14:01
  Speaker 2: the nutrients, manufacture of the vitamins, and hand over the
• 14:04
  Speaker 2: final product. It is a perfectly optimized symbiosis.
• 14:07
  Speaker 1: It's beautiful. Really, It's an evolutionary masterpiece. But I'm still
• 14:11
  Speaker 1: stuck on the risk factor. Well, think about the mechanics
• 14:14
  Speaker 1: of this. I have thirty eight trillion foreign bacteria, fungi, viruses,
• 14:19
  Speaker 1: and archaea living inside my gut. By definition, they are
• 14:23
  Speaker 1: alien entities. They are non human. How does the human
• 14:27
  Speaker 1: body tolerate this massive foreign presence without launching a full
• 14:31
  Speaker 1: scale nuclear immune attack every single second of the day.
• 14:35
  Speaker 1: I mean, if I get a tiny wooden splinter in
• 14:37
  Speaker 1: my finger, my immune system goes crazy, gets red, swollen
• 14:40
  Speaker 1: and flamed, filled with puss yep. But I have thirty
• 14:43
  Speaker 1: eight trillion bugs in my belly and nothing. How is
• 14:47
  Speaker 1: my body not constantly at war with my colon?
• 14:49
  Speaker 2: That is the multimillion dollar biological question, and the answer
• 14:53
  Speaker 2: is absolutely incredible. It brings us to this second major
• 14:56
  Speaker 2: function of the microbiome. It doesn't just feed us, it
• 14:59
  Speaker 2: actively manages defenses.
• 15:00
  Speaker 1: So, if we go back to the corporation analogy, we're
• 15:02
  Speaker 1: moving from the cafeteria to the security department exactly.
• 15:06
  Speaker 2: But to understand how the security department operates, you have
• 15:08
  Speaker 2: to realize where the headquarters is located. A staggering seventy
• 15:11
  Speaker 2: to eighty percent of the entire human immune system is
• 15:14
  Speaker 2: located directly in the gastrointestinal tract.
• 15:16
  Speaker 1: Cold. Then I'm going to push back on that seventy
• 15:18
  Speaker 1: to eighty percent, Yes, because when I get sick, when
• 15:21
  Speaker 1: I get a sore throat or a bad cold, the
• 15:23
  Speaker 1: lymph nodes in my neck swell up, my armpits ache,
• 15:26
  Speaker 1: I get a fever in my head and my muscles.
• 15:29
  Speaker 1: If the vast majority of my immune army is stationed
• 15:32
  Speaker 1: in my stomach, why does it feel like the war
• 15:35
  Speaker 1: is happening everywhere else?
• 15:36
  Speaker 2: That is a very intuitive pushback what you were describing.
• 15:39
  Speaker 2: The swollen lymph nodes the systemic feed That is your
• 15:42
  Speaker 2: body's systemic immune response to an active, spreading infection. It's
• 15:47
  Speaker 2: loud and noticeable, right, But the immune system in your
• 15:49
  Speaker 2: gut operates differently. It's called jault gut associated lymphoid tissue.
• 15:54
  Speaker 2: It is a massive, highly concentrated, silent garrison. It doesn't
• 15:59
  Speaker 2: usually causes stomach fever because its entire job is localized
• 16:02
  Speaker 2: containment and continuous surveillance.
• 16:04
  Speaker 1: Well, why station so many troops down there?
• 16:06
  Speaker 2: Because of the geography of the body. You have to
• 16:08
  Speaker 2: change how you visualize your anatomy. The gastro intestinal tract
• 16:12
  Speaker 2: is essentially a hollow tube that runs from your mouth
• 16:14
  Speaker 2: all the way to the other end. Topologically speaking, the
• 16:16
  Speaker 2: inside of that tube is actually the outside world.
• 16:19
  Speaker 1: Oh, that is a weird way to think about it,
• 16:21
  Speaker 1: but I guess it's true. It's like the hole in
• 16:23
  Speaker 1: a doughnut. The space inside the hole isn't the donut
• 16:25
  Speaker 1: itself exactly.
• 16:27
  Speaker 2: The food you eat, the dirt on an unwashed apple,
• 16:30
  Speaker 2: the pathogens you swallow, they are technically outside your body's
• 16:34
  Speaker 2: internal sterile environment the entire time they are moving through
• 16:38
  Speaker 2: your gut.
• 16:39
  Speaker 1: So my bloodstream and my internal organs are the dough
• 16:42
  Speaker 1: of the donut, and the food is just passing through
• 16:44
  Speaker 1: the hole, right.
• 16:45
  Speaker 2: And the border between that chaotic bacteria filled outside world,
• 16:49
  Speaker 2: and your sterile internal bloodstream is terrifyingly thin. The mucosal
• 16:55
  Speaker 2: lining of your gut, the epithelial layer, is only one
• 16:58
  Speaker 2: single cell thick.
• 17:00
  Speaker 1: One cell thick. Why would a primary border wall be
• 17:03
  Speaker 1: so thin.
• 17:04
  Speaker 2: It has to be thin so that the nutrients, the buterrate,
• 17:06
  Speaker 2: the vitamins we just talked about, can actually pass through
• 17:09
  Speaker 2: into the bloodstream. But because it's only one cell thick,
• 17:11
  Speaker 2: it is incredibly vulnerable. If that wall breaches, the thirty
• 17:15
  Speaker 2: eight trillion microbes sitting on the other side would flood
• 17:18
  Speaker 2: into your blood, causing lethal sepsis. It is the primary
• 17:21
  Speaker 2: border crossing where your biology directly interacts with the external environment.
• 17:26
  Speaker 2: And the total surface area of that lining, with all
• 17:28
  Speaker 2: its folds and vlie is massive, roughly the size of
• 17:32
  Speaker 2: a tennis court.
• 17:33
  Speaker 1: Okay, if I have a border the size of a
• 17:35
  Speaker 1: tennis court that is only one cell thick and there
• 17:37
  Speaker 1: are trillions of aliens on the other side, suddenly it
• 17:40
  Speaker 1: makes total sense. Why eighty percent of the military station
• 17:43
  Speaker 1: right there.
• 17:44
  Speaker 2: You put the army at the most vulnerable border. But
• 17:47
  Speaker 2: here's the catch. An army with no training is just
• 17:49
  Speaker 2: a panicked mob. The immune system has a ridiculously difficult job.
• 17:55
  Speaker 2: It has to look at a piece of digested broccoli,
• 17:57
  Speaker 2: a harmless probiotic bacterium, and a deadly strain of salmonella,
• 18:02
  Speaker 2: and it has to know exactly how to react to
• 18:04
  Speaker 2: each one instantly.
• 18:05
  Speaker 1: How does it learn the difference?
• 18:07
  Speaker 2: This is where the microbiome steps in. It acts as
• 18:09
  Speaker 2: an elite training academy for your immune cells. The beneficial
• 18:13
  Speaker 2: microbes actually communicate with your human immune cells.
• 18:16
  Speaker 1: How do a bacteria and a human immune cell talk
• 18:18
  Speaker 1: to each other?
• 18:19
  Speaker 2: Through a fascinating mechanism, You have specialized immune sentinels called
• 18:24
  Speaker 2: dendritic cells. Think of them like periscopes. They actually squeeze
• 18:28
  Speaker 2: their long arms through that one celfic lining, reach out
• 18:32
  Speaker 2: into the gut cavity, grab a sample of whatever is floating.
• 18:35
  Speaker 1: By, like a microbe or a food protein.
• 18:37
  Speaker 2: Yes, and they pull it back inside to present it
• 18:40
  Speaker 2: to the immune system's command center.
• 18:42
  Speaker 1: Hey boss, I found this. Is this a threat?
• 18:45
  Speaker 2: Exactly? They present it to what are called naive t cells.
• 18:49
  Speaker 2: These are foot soldiers that haven't received their orders yet. Now,
• 18:52
  Speaker 2: if your gut is filled with beneficial bacteria, those good
• 18:56
  Speaker 2: bacteria are constantly secreting specific chemical signals. For example, a
• 19:00
  Speaker 2: bacteria called bacteroids for Jellis produces a molecule called polysaccharide
• 19:05
  Speaker 2: a or PSA.
• 19:06
  Speaker 1: And what's BSA do?
• 19:07
  Speaker 2: When the dendritic cell presents a sample to the naive
• 19:10
  Speaker 2: T cell, the presence of that PSA molecule acts like
• 19:13
  Speaker 2: a calming instructor. It tells the T cell, Hey, the
• 19:16
  Speaker 2: environment is safe. This protein is friendly.
• 19:18
  Speaker 1: Wow.
• 19:18
  Speaker 2: This chemical instruction causes the naive T cell to transform
• 19:22
  Speaker 2: into a very specific type of cell called a T
• 19:24
  Speaker 2: regulatory cell or a t reg.
• 19:26
  Speaker 1: T regulatory cells, I assume they regulate things.
• 19:29
  Speaker 2: They are the ultimate peacekeepers. T REGs produce an anti
• 19:34
  Speaker 2: inflammatory chemical called interleukin ten or IL ten. They literally
• 19:38
  Speaker 2: bathe the border wall in a calming signal that tells
• 19:41
  Speaker 2: the rest of the immune system to stand down. They
• 19:44
  Speaker 2: teach tolerance. They say, this is just peanut protein. Relax,
• 19:47
  Speaker 2: It's just a friendly diffidobacterium. Do not attack.
• 19:51
  Speaker 1: So my own microbes are the ones suppressing my immune
• 19:54
  Speaker 1: system so it doesn't accidentally destroy my gut every time
• 19:57
  Speaker 1: I eat. Exactly, they are the reason I don't spontaneously
• 20:00
  Speaker 1: combusts from inflammation.
• 20:01
  Speaker 2: Precisely, they train the immune system to remain calm around
• 20:05
  Speaker 2: harmless stuff while ensuring it remains hypervigilant against genuine pathogenic threats.
• 20:10
  Speaker 2: But the defensive strategies of the microbiome go way beyond
• 20:13
  Speaker 2: just training our immune cells. The microbes themselves are active combatants.
• 20:17
  Speaker 1: Right, I've read about this. It's a concept called competitive exclusion.
• 20:20
  Speaker 1: Let's walk through how that works.
• 20:21
  Speaker 2: It's a very elegant, brutal form of defense. Imagine a
• 20:25
  Speaker 2: massive stadium with a million seats in a healthy gut,
• 20:29
  Speaker 2: Every single seat is filled by a friendly, beneficial microbe.
• 20:33
  Speaker 2: They are firmly attached to the receptors on your gut wall.
• 20:36
  Speaker 2: They are occupying all the physical space, and they are
• 20:38
  Speaker 2: consuming all the available nutrients.
• 20:40
  Speaker 1: So the stadium is sold out right now.
• 20:43
  Speaker 2: Suppose you accidentally eat some undercooked chicken and a dangerous
• 20:46
  Speaker 2: pathogen like salmonella or C. Difficile enters your gut. It
• 20:51
  Speaker 2: looks around trying to find a place to attach to
• 20:53
  Speaker 2: the wall so it can multiply and cause an infection.
• 20:56
  Speaker 2: But it realizes there's nowhere to sit. The good guys
• 20:59
  Speaker 2: won't give up their never, and worse for the pathogen,
• 21:02
  Speaker 2: there's no food. The good bacteria are incredibly efficient scavengers.
• 21:07
  Speaker 2: Some of them even deploy molecules called cider flores, which
• 21:11
  Speaker 2: act like chemical magnets to steal all the available iron
• 21:15
  Speaker 2: in the gut. Pathogens desperately need iron to multiply.
• 21:18
  Speaker 1: So Salmonella literally just gets starved out, has no place
• 21:21
  Speaker 1: to land, and just get flushed away in the next
• 21:23
  Speaker 1: bellel movement exactly.
• 21:24
  Speaker 2: The healthy bacteria prevent the dangerous ones from ever gaining
• 21:28
  Speaker 2: a foothold simply by aggressively taking up all the real
• 21:31
  Speaker 2: estate and resources. And on top of that, they maintain
• 21:34
  Speaker 2: what we call barrier integrity.
• 21:36
  Speaker 1: Going back to that onesell thick wall, how do they
• 21:39
  Speaker 1: fortify it?
• 21:40
  Speaker 2: The cells of your gut lining are stitched together by
• 21:43
  Speaker 2: proteins called tight junctions, specifically proteins known as claudins and occludins.
• 21:48
  Speaker 2: These act like the mortar between the bricks. The butyrate
• 21:51
  Speaker 2: we talked about earlier. It acts as a signaling molecule
• 21:54
  Speaker 2: that tells the human cells to keep those tight junctions
• 21:57
  Speaker 2: tightly sealed so.
• 21:58
  Speaker 1: No leaks right.
• 21:59
  Speaker 2: Furthermore, beneficial microbes constantly send chemical signals to specialized human
• 22:04
  Speaker 2: cells called goblet cells, telling them to produce a thick,
• 22:07
  Speaker 2: viscous layer of mucus Musin this mucus acts as a
• 22:11
  Speaker 2: physical mot a force field, keeping the bacteria at a
• 22:15
  Speaker 2: safe distance from the actual cell wall.
• 22:17
  Speaker 1: That is an incredibly complex, beautifully choreographed system. The microbes
• 22:22
  Speaker 1: train the peacekeepers, they starve out the invaders, and they
• 22:25
  Speaker 1: build a chemical force field. But what happens when that
• 22:28
  Speaker 1: ecosystem is disturbed? What happens if the stadium seeds empty.
• 22:32
  Speaker 2: Out, then you enter a state of dyspiosis. The ecosystem collapses,
• 22:36
  Speaker 2: and the consequences of dyspiosis are profound, largely because of
• 22:39
  Speaker 2: what happens to the immune system.
• 22:40
  Speaker 1: If the peacekeepers lose their instructors.
• 22:42
  Speaker 2: The immune system loses its mind. Without those signals, without
• 22:47
  Speaker 2: the creation of T regulatory cells producing calming aisle ten,
• 22:51
  Speaker 2: the immune system becomes deeply confused and dangerously hyperactive.
• 22:55
  Speaker 1: It makes me think of an over zealous bouncer at
• 22:57
  Speaker 1: a nightclub.
• 22:58
  Speaker 2: Okay, let's hear it.
• 22:59
  Speaker 1: When the microbiomi healthy, the microbes are like the VIPs.
• 23:02
  Speaker 1: They hold the clipboard, they stand next to the bouncer,
• 23:04
  Speaker 1: and they whisper in his ear, like, Hey, that peanut
• 23:07
  Speaker 1: protein is cool. Let him in. Oh the pollen, she's
• 23:10
  Speaker 1: a regular. She's fine. Wait, that's Salmonelli. Guy, throw them out.
• 23:13
  Speaker 1: But when dys biosis hits, when the ecosystem crashes, the
• 23:17
  Speaker 1: VIPs are gone. The bouncer drops the clipboard, he panics.
• 23:20
  Speaker 1: He just starts swinging his fists at absolutely everyone who
• 23:23
  Speaker 1: walks near the door.
• 23:24
  Speaker 2: That is a perfect analogy and that panicking bouncer. That
• 23:28
  Speaker 2: is exactly what a severe allergy or an autoimmune disease is.
• 23:32
  Speaker 2: Without the microbes there to enforce tolerance, the immune system
• 23:35
  Speaker 2: starts attacking harmless food proteins, which is how you develop
• 23:39
  Speaker 2: a sudden food allergy. It attacks environmental ellergens, leading to
• 23:42
  Speaker 2: asthma and autoimmunity.
• 23:44
  Speaker 1: When the body attacks.
• 23:45
  Speaker 2: Itself, that is the tragic end result. Sometimes, through a
• 23:48
  Speaker 2: process called molecular mimicry, the paniced immune system creates antibodies
• 23:52
  Speaker 2: to attack a rogue bacteria, but those antibodies accidentally cross
• 23:56
  Speaker 2: react with your own human tissue. It starts attacking your
• 24:00
  Speaker 2: joints in rheumatoid arthritis or your thyroid and hashimotos. Wow,
• 24:04
  Speaker 2: we now see a very clear direct through line from
• 24:07
  Speaker 2: a depleted microbiome dysbiosis to chronic systemic inflammation, and a
• 24:12
  Speaker 2: wide array of autoimmune conditions.
• 24:14
  Speaker 1: So these microscopic contractors dictate the fuel we get from
• 24:17
  Speaker 1: our food. They completely manage our security department and prevent
• 24:21
  Speaker 1: our immune system from destroying our own organs. That alone
• 24:25
  Speaker 1: is enough to change how I view my body forever.
• 24:28
  Speaker 1: But the science goes even deeper, doesn't it. Yeah, their
• 24:30
  Speaker 1: influence goes much much higher up the chain of command.
• 24:32
  Speaker 1: They aren't just talking to our immune cells down in
• 24:34
  Speaker 1: the basement.
• 24:35
  Speaker 2: No they are not. They have a direct red phone
• 24:37
  Speaker 2: hotline to the absolute top of the corporate ladder. They
• 24:40
  Speaker 2: are talking to the brain.
• 24:42
  Speaker 1: This is arguably the most frontier pushing area of biology
• 24:45
  Speaker 1: right now, the gut brain axis. The idea that the
• 24:49
  Speaker 1: bacteria in my intestines can dictate how I feel emotionally,
• 24:52
  Speaker 1: how I process stress. It almost sounds like pseudoscience until
• 24:56
  Speaker 1: you look at the mechanics. Let's start with the hardware.
• 24:59
  Speaker 1: How are bugs in my colon physically communicating with the
• 25:02
  Speaker 1: brain inside my skull?
• 25:04
  Speaker 2: Well, we have to start by acknowledging something called the
• 25:06
  Speaker 2: second brain. Most people have never heard of this, But
• 25:09
  Speaker 2: your gut contains its own entirely independent, highly sophisticated neural network.
• 25:14
  Speaker 2: It's called the enteric nervous system or ENS.
• 25:17
  Speaker 1: When you say neural network, you don't just mean a
• 25:19
  Speaker 1: few stray nerve endings.
• 25:20
  Speaker 2: I mean roughly five hundred million neurons woven directly into
• 25:24
  Speaker 2: the walls of your entire digestive tract. To put that
• 25:27
  Speaker 2: in perspective, your gut has more neurons than your entire
• 25:29
  Speaker 2: spinal cord.
• 25:30
  Speaker 1: Why does my stomach need half a billion brain cells?
• 25:33
  Speaker 2: Because digestion is wildly complicated. The ENS manages the complex
• 25:38
  Speaker 2: choreography of peristalsis the muscular contractions that move food along,
• 25:43
  Speaker 2: as well as the secretion of acids and enzymes and
• 25:45
  Speaker 2: the regulation of blood flow. It operates largely autonomously. I mean,
• 25:50
  Speaker 2: you don't have to consciously think about digesting your.
• 25:52
  Speaker 1: Lunch, thank god. Right.
• 25:54
  Speaker 2: But this second brain isn't isolated. It is in constant,
• 25:58
  Speaker 2: real time, lightning fastmmunication with the primary.
• 26:01
  Speaker 1: Brain in your skull, and the microbiome is hacking into
• 26:04
  Speaker 1: that communication line exactly.
• 26:06
  Speaker 2: They are heavily dictating the topic of the conversation, and
• 26:09
  Speaker 2: the way they do this is through chemical messengers. Let's
• 26:12
  Speaker 2: talk about neurotransmitter.
• 26:13
  Speaker 1: This is the statistic that completely stopped me in my tracks.
• 26:16
  Speaker 1: Let's talk about serotonin.
• 26:18
  Speaker 2: The famous happy chemical.
• 26:19
  Speaker 1: Right, because if you walk down the street and ask
• 26:22
  Speaker 1: anyone where serotonin is made, they will point to their head.
• 26:25
  Speaker 1: It regulates mood, it regulates sleep cycles, appetite, feelings of
• 26:29
  Speaker 1: overall well being. It is the primary target of almost
• 26:32
  Speaker 1: every major SSRI and a depressant medication on the market.
• 26:36
  Speaker 1: But the reality of where it comes from is totally different.
• 26:39
  Speaker 2: The reality is that roughly ninety percent of the body
• 26:42
  Speaker 2: serotonin is produced not in the brain but in the gut.
• 26:45
  Speaker 2: Ninety yes, and it is largely influenced, stimulated, and regulated
• 26:49
  Speaker 2: by your gut microbes. Your gut lining contains specialized cells
• 26:53
  Speaker 2: called enterrochromofin cells. These cells act as sensory organs. Okay,
• 26:58
  Speaker 2: When your beneficial bacteria produce certain metabolites, like those short
• 27:02
  Speaker 2: chain fatty acids we discussed, they stimulate these enterochromofin cells
• 27:06
  Speaker 2: to synthesize massive amounts of serotonin.
• 27:08
  Speaker 1: So my bacteria are literally telling my gut to pump
• 27:11
  Speaker 1: out the chemical that makes me feel happy and stable.
• 27:14
  Speaker 2: They are, and it doesn't stop at serotonin they are
• 27:17
  Speaker 2: also heavily involved in the production of GABA. What is
• 27:20
  Speaker 2: gabba gabba or gamma? Immino? Butyic acid is your brain's
• 27:24
  Speaker 2: primary inhibitory neurotransmitter. Its main job is to calm the
• 27:28
  Speaker 2: nervous system down, to turn down the volume on fear, anxiety,
• 27:31
  Speaker 2: and stress. Certain strains of bacteria, particularly in the lackt
• 27:35
  Speaker 2: of picillous and Biffidobacterium families, actually produce GABA directly.
• 27:39
  Speaker 1: Okay, So our gut bacteria are basically operating a massive
• 27:43
  Speaker 1: internal pharmaceutical plant, churning out the very chemicals that determine
• 27:47
  Speaker 1: whether we feel joyful and relaxed or utterly panicked. But
• 27:50
  Speaker 1: I have a mechanical question. Serotonin produced in the gut
• 27:55
  Speaker 1: can't cross the blood brain barrier, right, So how do
• 27:58
  Speaker 1: those chemicals are The signals they create actually reached the
• 28:01
  Speaker 1: brain to change my mood. They don't just float up
• 28:03
  Speaker 1: there in the blood.
• 28:04
  Speaker 2: No, they don't. They take the information super highway, specifically,
• 28:08
  Speaker 2: a massive bundle of nerves called the vegus nerve.
• 28:11
  Speaker 1: AH. The vegus nerve, I've heard it described as a
• 28:14
  Speaker 1: biological fiber optic cable.
• 28:16
  Speaker 2: That's exactly what it is vegas means wandering and lighten.
• 28:18
  Speaker 2: It is the tenth cranial nerve, and it is the
• 28:20
  Speaker 2: longest and most complex of the cranial nerves. It runs
• 28:23
  Speaker 2: all the way from the brainstem down through the neck
• 28:25
  Speaker 2: and chest, and branches out across the entire abdomen, physically
• 28:29
  Speaker 2: wrapping around the digestive tract. It is a hardwired electrical
• 28:32
  Speaker 2: connection between your gut and your brain.
• 28:34
  Speaker 1: And what's wild is that it's a two way street,
• 28:37
  Speaker 1: but the traffic isn't equal. I read that about eighty
• 28:40
  Speaker 1: percent of the fibers in the vegus nerve are afferent,
• 28:43
  Speaker 1: meaning they are sending signals up from the gut to
• 28:46
  Speaker 1: the brain, rather than the brain sending commands down to
• 28:49
  Speaker 1: the gut.
• 28:49
  Speaker 2: That is correct. The brain is basically just sitting there
• 28:52
  Speaker 2: acting as a receiver, constantly getting a status report from
• 28:55
  Speaker 2: the microbiome.
• 28:56
  Speaker 1: How does the signal actually bridge the gap from a
• 28:59
  Speaker 1: bacteria to the nerve.
• 29:00
  Speaker 2: We recently discovered that certain cells in the gut lining
• 29:03
  Speaker 2: called enterroendocrine cells, actually possess physical foot like protrusions called neuropods.
• 29:10
  Speaker 2: These neuropods form direct synapse like connections with the endings
• 29:14
  Speaker 2: of the vegus nerve. Oh wow, So a bacteria produces
• 29:17
  Speaker 2: a chemical The enerendocrine cell senses it, and within milliseconds
• 29:21
  Speaker 2: it fires an action potential up the vagus nerve straight
• 29:24
  Speaker 2: into the brain stem. It is continuous, real time streaming
• 29:27
  Speaker 2: of ecological data to your brain.
• 29:29
  Speaker 1: But just like the immune system, there is a dark
• 29:32
  Speaker 1: side to this connection. The vagus nerve just transmits whatever's happening.
• 29:37
  Speaker 1: What happens when the message is being sent up the
• 29:39
  Speaker 1: fiber optic cable are distress signals. What happens when the
• 29:43
  Speaker 1: gut is in a state of severe dysbiosis.
• 29:45
  Speaker 2: This is where the gut brain access gets incredibly critical
• 29:48
  Speaker 2: for mental health. We mentioned earlier that microbial imbalance and
• 29:52
  Speaker 2: the loss of that protective nucostal barrier triggers low grade
• 29:55
  Speaker 2: systemic inflammation. The bouncer starts swinging, the tight junctions breakdown,
• 30:00
  Speaker 2: causing what is commonly known as leaky gut.
• 30:02
  Speaker 1: And when the gut leaks, what gets out toxins.
• 30:05
  Speaker 2: Specifically, a highly inflammatory molecule called luppo polysaccharide or LPs.
• 30:11
  Speaker 2: LPs is an endotoxin found in the cell walls of
• 30:14
  Speaker 2: certain pathogenic bacteria. When it leaks through the gut wall
• 30:17
  Speaker 2: and into the bloodstream, your immune system freaks out. Naturally,
• 30:20
  Speaker 2: the immune cells release a flood of inflammatory molecules called cytokines,
• 30:24
  Speaker 2: specifically things like INTERLEUCN six and TNF alpha.
• 30:27
  Speaker 1: And those cytokines circulating in the blood are serious.
• 30:30
  Speaker 2: Trouble, severe trouble because they travel throughout the vascular system
• 30:33
  Speaker 2: and when they reach the brain, they can actually compromise
• 30:36
  Speaker 2: the blood brain barrier.
• 30:38
  Speaker 1: Wait, the blood brain barrier is supposed to be the
• 30:40
  Speaker 1: ultimate fortress wall. It's an impenetrable shield designed to keep
• 30:44
  Speaker 1: pathogens and toxins out of our delicate brain tissue.
• 30:47
  Speaker 2: It is under normal circumstances, but systemic chronic inflammation degrades
• 30:52
  Speaker 2: that barrier. The enofelial cells that make up the barrier
• 30:55
  Speaker 2: begin to loosen. These inflammatory cytokines slip through into the
• 30:59
  Speaker 2: brain tissue, and when they do, they activate the brain's
• 31:02
  Speaker 2: own resident immune cells called microglia.
• 31:04
  Speaker 1: And what do microglia do when they are activated by
• 31:07
  Speaker 1: these cytokinds.
• 31:08
  Speaker 2: They go into attack mode. They release localized inflammatory chemicals
• 31:12
  Speaker 2: right inside the brain. This is called neuroinflammation. Your brain
• 31:15
  Speaker 2: is literally inflamed, and modern neuroscience is now drawing incredibly strong,
• 31:20
  Speaker 2: undeniable mechanistic links between this gut born neuroinflammation and profound psychological.
• 31:27
  Speaker 1: Symptoms and kind symptoms.
• 31:28
  Speaker 2: When the brain is inflamed, it alters the way neurotransmitters
• 31:31
  Speaker 2: are metabolized, It reduces neuroplasticity. This manifests physically and psychologically
• 31:36
  Speaker 2: as severe brain fog, deep clinical anxiety, and hodonia, which
• 31:40
  Speaker 2: is the inability to feel pleasure and major depressive disorder.
• 31:44
  Speaker 1: So I have to ask a really uncomfortable, slightly unsettling
• 31:47
  Speaker 1: question here coved. Next time I feel inexplicably anxious, or
• 31:51
  Speaker 1: I wake up feeling this heavy, unshakable sadness, I have
• 31:55
  Speaker 1: to wonder, am I actually depressed because of my life's
• 31:58
  Speaker 1: circumstances processing emotional trauma? Or are my gut bacteria just
• 32:04
  Speaker 1: at a whack. Are my tight junctions leaking LPs into
• 32:07
  Speaker 1: my blood causing cytokines to cross my blood brain barrier
• 32:10
  Speaker 1: and inflame my microglia? Is my profound psychological state just
• 32:14
  Speaker 1: an ecological feedback loop.
• 32:16
  Speaker 2: It is a staggering question, and it reframes mental health
• 32:18
  Speaker 2: in a profound way. It's not to say that trauma
• 32:20
  Speaker 2: or life circumstances don't cause depression. Of course they do.
• 32:23
  Speaker 2: But if narrow inflammation driven by gut dis biosis is
• 32:26
  Speaker 2: a root biological cause of these feelings for millions of people,
• 32:29
  Speaker 2: then all the cognitive behavioral therapy and talk therapy in
• 32:31
  Speaker 2: the world isn't going to fully.
• 32:33
  Speaker 1: Solve the problem right because the root is biological.
• 32:36
  Speaker 2: You cannot think your way out of a burning building.
• 32:38
  Speaker 2: If the fire is biological, your brain is essentially on
• 32:42
  Speaker 2: fire because your microbes are sending up the smoke. You
• 32:45
  Speaker 2: have to fix the ecosystem in your gut.
• 32:47
  Speaker 1: It is both terrifying to realize how little control we
• 32:49
  Speaker 1: have and incredibly validating. Anyone who has ever had butterflies
• 32:54
  Speaker 1: in their stomach before a big public speech or felt
• 32:57
  Speaker 1: physically nauseous from intense grief knows that the gut and
• 33:01
  Speaker 1: the brain are deeply connected, absolutely, But to know the
• 33:04
  Speaker 1: actual mechanics that the microscopic bugs inside us are pulling
• 33:08
  Speaker 1: the strings of our emotions through cytokines and the vaguus nerve,
• 33:12
  Speaker 1: it's a lot to.
• 33:12
  Speaker 2: Process, which brings us to the ultimate practical question, if
• 33:16
  Speaker 2: we are this profoundly influenced by our microscopic inhabitants, if
• 33:20
  Speaker 2: they dictate the fuel we extract, if they control our
• 33:23
  Speaker 2: immune defenses, and if they literally manufacture the neurotransmitters that
• 33:26
  Speaker 2: dictate our mood and our sanity.
• 33:29
  Speaker 1: How do we take back the reins? How do we
• 33:31
  Speaker 1: fix the ecosystem?
• 33:32
  Speaker 2: Exactly?
• 33:33
  Speaker 1: Yes? How do I, as the CEO, negotiate with these
• 33:36
  Speaker 1: unruly contractors? Give me the manual.
• 33:38
  Speaker 2: The very first step requires a fundamental shift in your
• 33:41
  Speaker 2: personal identity. You have to completely stop thinking of yourself
• 33:45
  Speaker 2: as a solitary individual trying to follow a diet to
• 33:48
  Speaker 2: lose weight or stay healthy.
• 33:49
  Speaker 1: Okay, if I'm not an individual on a diet, what
• 33:52
  Speaker 1: am I?
• 33:52
  Speaker 2: You are a forest manager? You are a park ranger.
• 33:55
  Speaker 2: Your body is a highly complex habitat, and your daily
• 33:59
  Speaker 2: lifestyle choices dictate the climate of that habitat. You, the manager,
• 34:03
  Speaker 2: decide which species in your internal garden thrive and multiply
• 34:07
  Speaker 2: and which ones go extinct.
• 34:09
  Speaker 1: I love that paradigm shift the forest manager. So if
• 34:12
  Speaker 1: I'm the manager, how do I actually build and maintain
• 34:15
  Speaker 1: this ecosystem? What is the biological action plan?
• 34:18
  Speaker 2: It starts with the absolute foundation, the one thing we
• 34:20
  Speaker 2: brought up at the very beginning. High dietary fiber.
• 34:23
  Speaker 1: The complex carbohydrates with the beta bunds the fertilizer.
• 34:26
  Speaker 2: Exactly. Fiber is the primary exclusive food source for your
• 34:29
  Speaker 2: most beneficial microbes. When you eat a diet high and
• 34:32
  Speaker 2: diverse plant fibers, beans, lentils, oats, a wide, colorful variety
• 34:37
  Speaker 2: of vegetables, you are dumping high quality fertilizer onto your
• 34:40
  Speaker 2: internal forest. You are specifically feeding the keystone species.
• 34:44
  Speaker 1: Can you give me an example of a keystone species
• 34:46
  Speaker 1: we want to feed?
• 34:47
  Speaker 2: A perfect example is a bacterium called Akermansia musiniphila Akermanzia musiniphilo.
• 34:53
  Speaker 1: What does it do?
• 34:54
  Speaker 2: The name literally translates to musin loving. This bacteria is
• 34:59
  Speaker 2: fast because it doesn't actually eat the food you eat.
• 35:02
  Speaker 2: It lives right on the border wall and eats the
• 35:05
  Speaker 2: mucus layer itself.
• 35:06
  Speaker 1: Wait, hold on, you just told me the mucus layer
• 35:08
  Speaker 1: is my protective force field against pathogens. Why would I
• 35:11
  Speaker 1: want a bacteria eating my shield. That sounds terrible, It.
• 35:15
  Speaker 2: Sounds paradoxical, But think of it like pruning a hedge
• 35:18
  Speaker 2: in your garden by constantly grazing on impruning the mucus layer.
• 35:22
  Speaker 2: Acromansia acts as a signal to your human goblet cells,
• 35:26
  Speaker 2: stimulating them to produce more mucous faster. It keeps the
• 35:29
  Speaker 2: mucus layer thick, fresh and highly protective.
• 35:32
  Speaker 1: Oh that makes sense.
• 35:33
  Speaker 2: But Acromansia needs a healthy, fiber rich environment to thrive. Furthermore,
• 35:38
  Speaker 2: when these keystone species break down fiber, they engage in
• 35:41
  Speaker 2: something called cross feeding.
• 35:43
  Speaker 1: What is crossfeeding?
• 35:44
  Speaker 2: The waste product of one beneficial bacteria becomes the primary
• 35:48
  Speaker 2: food source for another beneficial bacteria. It's a cascading web
• 35:52
  Speaker 2: of life. And the ultimate end product of all this
• 35:54
  Speaker 2: fiber digestion, as we know, is the massive production of butyrate,
• 35:58
  Speaker 2: which heals the leak gut and lowers the inflammation.
• 36:02
  Speaker 1: Okay, so fiber is the ultimate fertilizer. But what if
• 36:05
  Speaker 1: the forest has already been burned down? What if I've
• 36:08
  Speaker 1: eaten a terrible diet of processed food for twenty years
• 36:11
  Speaker 1: and I simply don't have enough of the good bacteria
• 36:13
  Speaker 1: left to feed. What if my stadium is empty?
• 36:17
  Speaker 2: That is where fermented foods come into play.
• 36:19
  Speaker 1: We're talking about things like authentic kimchi, kyfer traditional yogurt,
• 36:23
  Speaker 1: raw sauerkraut, kombucha right, And.
• 36:25
  Speaker 2: You need to understand that eating fermented foods achieves an
• 36:28
  Speaker 2: entirely different biological goal than eating fiber. Fiber feeds the
• 36:32
  Speaker 2: resident microbes you already have Clmented foods are like directly
• 36:35
  Speaker 2: planting new, live, beneficial seeds into the soil. Okay, These
• 36:39
  Speaker 2: foods are teeming with billions of live bacterial streams, mostly
• 36:43
  Speaker 2: Lectobacillus and Biffidobacterium. You are introducing fresh troops into the ecosystem.
• 36:48
  Speaker 1: Do they set up permanent camp in my gut?
• 36:50
  Speaker 2: Interestingly no, Most probiotics from fermented foods are transient. They
• 36:55
  Speaker 2: pass through your system over a few days. But while
• 36:58
  Speaker 2: they're moving through, they dramatically alter the environment. They lower
• 37:02
  Speaker 2: the pH of the gut, making it slightly more acidic,
• 37:05
  Speaker 2: which is incredibly hostile to pathogenic bacteria, but absolutely perfect
• 37:09
  Speaker 2: for your own resident good bacteria to multiply and reclaim
• 37:13
  Speaker 2: those stadium seats.
• 37:14
  Speaker 1: Okay, So fiber is the rain and the soil providing
• 37:17
  Speaker 1: the daily nourishment. Frmended foods are the new saplings that
• 37:21
  Speaker 1: change the microclimate. That is how we build the forest.
• 37:25
  Speaker 1: But as a manager, I also need to know how
• 37:27
  Speaker 1: we accidentally destroy the ecosystem because we have a remarkable
• 37:31
  Speaker 1: capacity to ruin our gut health, often without even realizing it.
• 37:34
  Speaker 2: We do. And the most insidious, widespread destroyer isn't necessarily
• 37:38
  Speaker 2: a bad food like a processed dona, it's chronic stress.
• 37:42
  Speaker 1: This one is huge. I think culturally we all tend
• 37:45
  Speaker 1: to dismiss stress as something that is just in our head.
• 37:47
  Speaker 1: You know, I'm just stressed about this deadline. I'll take
• 37:49
  Speaker 1: a deep breath and get over it. We treat it
• 37:51
  Speaker 1: like an ephemeral emotion.
• 37:53
  Speaker 2: But as we've established with the gut brain access, nothing
• 37:56
  Speaker 2: is just in your head. It is a two way street.
• 37:59
  Speaker 2: When you are chronic stressed, When you are constantly worried
• 38:02
  Speaker 2: about work or finances or bad relationship, your brain is
• 38:05
  Speaker 2: in a perpetual state of sympathetic nervous system activation fight
• 38:09
  Speaker 2: or flight mode.
• 38:10
  Speaker 1: And how does my brain being in fight or flight
• 38:13
  Speaker 1: physically affect the microbes in my colon?
• 38:16
  Speaker 2: It is mechanically devastating. When your brain perceives chronic stress,
• 38:20
  Speaker 2: it floods your system with cortisol and adrenaline. Evolutionary speaking,
• 38:24
  Speaker 2: if you are running from a tiger, your body doesn't
• 38:26
  Speaker 2: care about digesting lunch, so the brain severely reduces blood
• 38:30
  Speaker 2: flow to the gastintestinal tract.
• 38:32
  Speaker 1: It reroutes the blood to the muscles exactly.
• 38:35
  Speaker 2: This creates a state of low grade aeschemia, lack of
• 38:37
  Speaker 2: oxygen and blood in the gut. This physical change slows
• 38:41
  Speaker 2: down motility, meaning food sits longer and ferments in the
• 38:44
  Speaker 2: wrong ways. The altered blood flow reduces the production of
• 38:47
  Speaker 2: that protective mucus layer, and most critically, high cortisol literally
• 38:52
  Speaker 2: alters the permeability of the gut lining. It forcefully pulls
• 38:55
  Speaker 2: apart those tight junctions we talked about.
• 38:57
  Speaker 1: So stress directly mechanically causes leaky gut.
• 39:00
  Speaker 2: Yes, and within days of this hostile, low mucous, highly
• 39:05
  Speaker 2: permeable environment, microbial diversity slashes. The good bacteria start zying
• 39:11
  Speaker 2: off in droves because the chemical climate of your gut
• 39:13
  Speaker 2: has become toxic to them.
• 39:15
  Speaker 1: So merely being stressed out literally kills off my beneficial
• 39:19
  Speaker 1: contractors and breaks down my border wall. That is awful,
• 39:22
  Speaker 1: but there is an even more direct nuclear weapon we
• 39:26
  Speaker 1: use on our microbiome, right, antibiotics.
• 39:29
  Speaker 2: We have to approach antibiotics with nuance. They are a
• 39:31
  Speaker 2: miracle of modern medicine. They have saved countless millions of lives.
• 39:35
  Speaker 2: If you have a life threatening staff infection or bacterial pneumonia,
• 39:39
  Speaker 2: antibiotics are absolutely necessary. You take them, but we have
• 39:42
  Speaker 2: to understand what they do ecologically right.
• 39:44
  Speaker 1: They aren't smart bombs. They are a broad spectrum weed killer.
• 39:47
  Speaker 2: They are completely indiscriminate. A broad spectrum antibiotic does not
• 39:50
  Speaker 2: possess the capability to distinguish between the pathogenic bacteria causing
• 39:54
  Speaker 2: your sinus infection and the beneficial biffidobacteria producing your serotonin
• 39:58
  Speaker 2: and protecting your gut lining. It sweeps through the colon
• 40:01
  Speaker 2: and wipes out the good with the bad, leaving the
• 40:03
  Speaker 2: forest barren and scorched.
• 40:05
  Speaker 1: And I imagine a barren forest is the perfect place
• 40:07
  Speaker 1: for bad weeds to subtly take over.
• 40:09
  Speaker 2: Exactly that is why seed to ficile infections are so
• 40:13
  Speaker 2: common in hospitals. After a patient receives heavy antibiotics, the
• 40:17
  Speaker 2: stadium is empty, so the pathogen takes a seat and
• 40:19
  Speaker 2: multiplies rapidly, and recovering from an antibiotic course requires highly deliberate,
• 40:24
  Speaker 2: careful rehabilitation of the gut using massive amounts of fiber
• 40:28
  Speaker 2: and fermented foods.
• 40:29
  Speaker 1: Okay, I want to summarize this whole lifestyle aspect to
• 40:32
  Speaker 1: make sure the forest manager manual is clear. Taking a
• 40:35
  Speaker 1: broad spectrum antibiotic is like dropping chemical napalm on your forest.
• 40:40
  Speaker 1: Chronic psychological stress is like causing a massive, agonizing drought
• 40:44
  Speaker 1: that dries up the protective rivers. Eating fermented foods is
• 40:47
  Speaker 1: like deliberately planting new fragile saplings in the dirt to
• 40:51
  Speaker 1: revitalize the area spot on, but eating high amounts of
• 40:54
  Speaker 1: diverse dietary fiber that is providing the rain, the rich
• 40:57
  Speaker 1: soil in the sunlight. Those saplings apps sely need to
• 41:00
  Speaker 1: grow deep roots and survive long term.
• 41:02
  Speaker 2: That is a phenomenal, perfectly accurate summary. And what's truly
• 41:06
  Speaker 2: empowering about this biological knowledge is the timeline. The microbiome
• 41:10
  Speaker 2: is incredibly dynamic. It isn't like human genetics, which are
• 41:13
  Speaker 2: static and permanent.
• 41:15
  Speaker 1: Right, if I have the human gene for brown eyes,
• 41:17
  Speaker 1: I have brown eyes. There's no changing line exactly.
• 41:19
  Speaker 2: You are stunk with your human genome. But because bacteria
• 41:22
  Speaker 2: reproduce so rapidly, some strains doubling their population every twenty minutes,
• 41:27
  Speaker 2: your microbiome responds to your choices almost immediately. Research shows
• 41:32
  Speaker 2: that you can significantly shift the composition and metabolic output
• 41:35
  Speaker 2: of your gut bacteria in as little as twenty four
• 41:38
  Speaker 2: to forty eight hours just by changing what you eat.
• 41:40
  Speaker 1: Wait twenty four hours. If I eat a massive bowl
• 41:43
  Speaker 1: of lentils and sauerkraut today, my contractors are already upbraiding
• 41:46
  Speaker 1: the facility. By tomorrow.
• 41:48
  Speaker 2: Yes, you are never stuck, no matter how much damage
• 41:50
  Speaker 2: has been done. You have the profound, immediate power to
• 41:53
  Speaker 2: reshape your biology, to rewrite the rules of your internal ecosystem,
• 41:57
  Speaker 2: meal by meal, day by day.
• 41:59
  Speaker 1: So bringing this entire journey full circle, you wake up tomorrow,
• 42:04
  Speaker 1: you walk into the bathroom, You look in the mirror.
• 42:06
  Speaker 1: You don't see an individual anymore. You see a world.
• 42:09
  Speaker 1: You see a walking, breathing planet.
• 42:11
  Speaker 2: It really is a beautiful way to see yourself.
• 42:13
  Speaker 1: Treating your body like an interconnected ecosystem rather than a
• 42:16
  Speaker 1: mechanical combuction engine is the ultimate key to human health.
• 42:21
  Speaker 1: When you actively care for your trillions of tiny inhabitants,
• 42:26
  Speaker 1: when you feed them the fiber they crave, when you
• 42:28
  Speaker 1: protect them from chronic stress, and when you cultivate their diversity,
• 42:32
  Speaker 1: they return the favor tenfold.
• 42:34
  Speaker 2: They absolutely do.
• 42:35
  Speaker 1: They flawlessly run your metabolism, They aggressively defend your borders
• 42:39
  Speaker 1: against disease, and they literally keep your mind clear, resilient,
• 42:42
  Speaker 1: and stable.
• 42:43
  Speaker 2: They are the ultimate symbiotic partners. You care for the habitat,
• 42:47
  Speaker 2: and the habitat cares for you.
• 42:48
  Speaker 1: But before we wrap this up, I want to leave
• 42:50
  Speaker 1: you the listener with a final slightly provocative philosophical twist,
• 42:56
  Speaker 1: something to ponder the next time you look at a
• 42:58
  Speaker 1: menu or open your refrigerator. We've spent this time talking
• 43:02
  Speaker 1: about how our microbes heavily direct our digestion. We've detailed
• 43:06
  Speaker 1: how they shape our immune reactions. We've even established the
• 43:09
  Speaker 1: mechanics of how they manufactured the very neurotransmitters that dictate
• 43:13
  Speaker 1: our moods and our feelings.
• 43:14
  Speaker 2: Yep, they are highly influential.
• 43:16
  Speaker 1: So if they control all of that, how much of
• 43:18
  Speaker 1: what we call free will is actually our own?
• 43:22
  Speaker 2: That is the ultimate slightly terrifying question, isn't it?
• 43:25
  Speaker 1: Think about it? Mechanically, we know that certain parasites like
• 43:28
  Speaker 1: Toxoplasma gandhi can literally hijack a mouse's brain to make
• 43:32
  Speaker 1: it lose its fear of cats. If a parasite can
• 43:35
  Speaker 1: control a mouse, what are our microbes doing to us?
• 43:38
  Speaker 1: It makes you wonder when you were sitting at your
• 43:40
  Speaker 1: desk at three pm and you desperately crave a sugary doughnut,
• 43:44
  Speaker 1: when you feel that undeniable, almost physical urge for junk food,
• 43:49
  Speaker 1: is that you're craving or is it a specific overgrown
• 43:52
  Speaker 1: population of sugar loving bacteria or yeast sitting in your
• 43:56
  Speaker 1: intestines chemically manipulating your vagus nerve and firing action potentials
• 44:01
  Speaker 1: into your brainstem to make you feed them exactly what
• 44:04
  Speaker 1: they want.
• 44:04
  Speaker 2: Are you making a conscious choice or are you just
• 44:07
  Speaker 2: following a biochemical order from the microscopic committee?
• 44:10
  Speaker 1: Exactly? You aren't just eating for yourself. You never have been.
• 44:13
  Speaker 1: You are constantly silently negotiating with a trillion strong microscopic
• 44:18
  Speaker 1: committee that has its own evolutionary agenda. Just keep that
• 44:21
  Speaker 1: in mind the next time you sit down for dinner.
• 44:23
  Speaker 1: Are you the CEO or are the contractors actually running
• 44:26
  Speaker 1: the show