Stuff You Should Know - SYSK Selects: How The Human Microbiome Project Works

Episode Date: August 15, 2020

If it was possible to take a full scan of all of the DNA of every cell in and on your body the results would be startling: Only 1 percent would be human. The other 99 percent comprises all of the bacteria, fungi, viruses and other microbes you literally cannot live without. Learn more in this classic episode. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

this season on Running the Break with CJ and Alex. Rapper Meek Mill, so obviously huge ties to Philly was at a Sixers game recently and in what seemed like a real-life curb your enthusiasm as an episode, he accidentally tripped a ref sitting courtside as the ref was running back up court. You know what CJ? I gotta say, I feel like that should be a technical foul, one free throw for the opposing team. Yes, if you rep your town and your team as much as you do Meek Mill, that he's a Sixer, right? So the opposing team's got to take free throws or unless, you know, if we're going off of the curb episode, does Meek have the discography of that compares to like

Seinfeld tapes that he could bring to the ref's, you know, hospital bed? Shout out to curb, that was one of the greatest episodes ever. Listen to Running the Break with CJ and Alex on the iHeart Radio app, Apple podcast, or wherever you get your podcasts. Brought to you by FanDuel, make every moment more with FanDuel Sportsbook, an official partner of the NBA. You know, when you're staying at an Airbnb, it might have crossed your mind, could my place be an Airbnb? And if it could, what could it earn? You could be sitting on an Airbnb and not even know it. Like maybe you have a spare bedroom where friends or family crash every once in a while, but when it's sitting empty, you could Airbnb it to help pay for some bills or,

I don't know, something more fun. Either way, your home might be worth more than you think. Find out how much at airbnb.ca slash host. Hey, everybody, it's me, Josh, and for this week's SYSK Selects, I've chosen how the Human Microbiome Project works, which we released back in May of 2014. And even after all these years, six years on, this information is still just totally mind blowing to me. And I love it. It's one of my favorite episodes of all time. I kind of forgotten about it and discovered it again. So I hope you enjoy it as much as I did. Welcome to Step You Should Know, a production of iHeartRadio's How Stuff Works. Hey, and welcome to the podcast. I'm Josh Clark. I almost just forgot what I was going to say.

Your name? Yeah. Wow. There's Charles W. Chuck Bright, piping in. Yep. And there's Trio. The trifecta. And this terrible iKia lamp. You think? Well, we are getting a little heat off of it right now. It's just nice. Did you ever see that iKia commercial about the lamp that was thrown out on the street? No. It was really good. Well, what happened to it? Was it like the monkey at the iKia? No, it was like a lamp gets thrown out with like someone's just redoing parts of their apartment and the lamp is kicked to the curb as it were. Computer animated. So it's human formed. Okay. Not human formed, what am I saying? Anthropogenic. Yeah. Anthropomorphized. And like looks up at the apartment that he was just thrown out of and stuff like that. Does he go back to

Sweden? I don't remember how it ends. Huh. I don't even know. You just remember the lamp like turns all human? It was sad. It was like sad. Okay. I got teared up. Did you go buy one of those lamps? No, of course. I didn't work. No. So I guess you're feeling pretty good since you're talking about lamps and everything. You know me and lamps. I do. That means it's a good day. It's a clear signal. Chuck's in a good mood, everybody. You know one of the reasons why you're in a good mood? Because your guts are functioning properly. Yeah. Yeah. Ish. Yeah. You know me. It's day to day. Yeah. With my stomach. Well, that's exactly right. Things change very quickly. Yeah. Because of your stomach and your stomach can't affect your mood. As a matter of fact, the vast majority of

the serotonin, which is a mood stabilizing neurotransmitter is produced in your gut. Yeah. And the way that things like serotonin and other stuff is produced is thanks to our microbiome, dude. Yeah. Our microbiome. This is the most fascinating thing going on in medicine science right now. Yeah. I get the impression reading various articles when scientists talk about it. They all seem really pumped up. It's like the breakthrough of the 21st century. And this thing like just started. It's 2014. Yeah. And like this could remain the breakthrough of the century. Yeah. And I mean, if you think about the timeline, up until the 20th century, you were like a plant or an animal. Right. And then it was literally like the 1950s and 60s that they started saying,

maybe we should break things down a little further and they came up with the five kingdoms. Right. I think they're now even as a sixth kingdom. Well, there's three domains now. Yeah. Eight kingdoms. Oh, there's eight? There's eight. And three, two of the domains are accounted for two of the kingdoms as well, bacteria and archaea. Yeah. And archaea used to be thought that they were the same as bacteria. Yes. Then they started looking into them a little more and they're like, oh, these guys are made up of different amino acids and they have different characteristics. And archaea, for example, are the kind of microbial life that you'll only find around undersea hot water sulfur vents. Yeah. Like volcanoes. Crazy places. Not in your vagina

or in your mouth. Well, no, because they're extremophiles and a vagina or a mouth isn't that extreme. Well, it is because archaea lives there. That's right. So the fact that we figured out that archaea are different than bacteria and not only that they don't just live in extreme environments but also on the human body, that was something we can thank the human microbiome project for. Yeah. And that wasn't, I think they didn't even discover archaea till the 1970s. So all this stuff is brand new and exciting. And by the way, the three domains are bacteria, archaea, and eukaryotes, which are us. Yes. Or eukaryotes because we have nucleus as nuclei. Yeah. Let's talk about this, man. We have before, I'm sure you remember, in the fecal transplant

episode. Yes. Because it definitely factors into it. You can. Poop shakes. Yeah. You can cure claustridium difficile, which is something where that it's a gut microbe. It's very harmful to humans that can colonize your guts after you take antibiotics, which is basically just like a slash and burn approach, which again, thanks to the human microbiome project, we're starting to understand, we might want to use antibiotics because what we used to just think of as almost entirely bad are actually mostly beneficial. Sure. And even some of the bad bacteria, aka germs, are actually present in our microbiome and normally live in harmony. Yeah. It just appears that when the microbiome gets out of whack, that's when disease happens.

Yeah. Like you may have E. Coli in your body right now. Yeah, I probably do. But it's not a big deal if you're... We always talk about stasis. Homeostasis. Yeah. Keeping things balanced in life is the key. Yes. And it's definitely the key with your own personal microbiome, which we have learned is very individualized, which we'll get to with the project. Right. So if you take a human body and you scanned all the genes in it, what you would find is there are about a hundred times more microbial genes than human genes in a genetic scan of a human body. Yeah. Our human cells only make up about 10% of the cells in the body. And here's another great stat. We actually... The healthiest person on the planet has between two and five

pounds of bacteria, pounds. Yeah. Of your body weight, about up to five pounds. Is it kind of... Yes. What's crazy is that that's even considering that microbial cells are anywhere from a tenth to a hundredth the size of an average human cell. Yeah. So do you know how much five pounds would have to... That adds up to quite a few. Yeah. As a matter of fact, there's an estimated 100 trillion microbes on an average human person. Just in, on, and a part of. Such a part of us and our normal functioning that we're finding very quickly that they're pretty much interchangeable. They are one with us and as their host, we are kind of one with them. Yeah. Like you have fungus on your skin. Yeah. No big deal, right? Well, that's another thing too we should talk about.

When people say microbe, it's kind of a catch-all word for... Tiny. Yeah. Any tiny, typically unicellular life and that's the case here too. But it doesn't just mean bacteria. The human microbiome is made up of lots of bacteria and lots of different types of bacteria. For example, the mouth may have up to 5,000 different species of bacteria. Yeah. And they're not just lazing around in your body. They are responsible for keeping your body in check or sometimes responsible for it being out of whack. Right. But they're all doing something or laying there waiting to do something. You also have what's called a virome. You have viruses in your microbiome and they appear to

be present to keep the bacteria populations from getting out of control. Like they're there to infect bacteria to kill them off and it's kind of like they're the lions to the gazelles of the microbiome. Okay. You take away the lions, you got too many gazelles. Yeah. They all start to starve. They don't function correctly. They may even eat each other. You don't want to see a gazelle eat another gazelle. So you have lions there and the lions, these apex predators, keep the gazelle population in check and ultimately healthy paradoxically. Yeah. It's the same thing with the virome in your microbiome. Yeah. We know they like gut bacteria, AIDS digestion and we'll get the gut bacteria more. I mean they're discovering just all kinds of

things it affects. Right. Synthesize vitamins. When you poop in the toilet and you look at your poop, which you should do by the way, on a regular basis. How much is it? Is it half? I've seen anywhere from a third to half. So a third to half of that is microbial biomass. It's not food. No. It's like dead and living bacteria that you're pooping out. Yeah. About half. Half. I saw something that was kind of mind-blowing too. It's really neat and accurate, especially on a microbial level. All right. To imagine your alimentary system, your digestive system. Yeah. As the inside of that is technically outside of your body. You have a hole, a trail running through the middle of your body. Yeah. That is attached to the outside world. That's

technically the outside. Yeah. I guess I see what you mean. Just chew on it for a minute. Yeah. Like the inside of your digestive system is technically the outside of your body. Like, ain't her? That's outside of your body. Yeah. It's confusing. It is, but once your head wraps around it, it's like one hand clapping kind of thing. Right. And you're just like, whoa, that is neat. All right. So that's I guess the briefest of overviews of microbes and bacteria, which we've talked about ad nauseam on the show. Yeah. And our great digestion podcast. That was one of my favorite ones. And then we've already talked about the poop shakes. So the National Institutes of Health came up with a plan, got some money together and said,

let's try and do what the human genome project did. Let's try and map out the micro, the human microbiome, which is a very tough task because everyone is different. Well, yeah, everyone's microbiome is different. And I just saw today it was released from University of Michigan. They've kind of already determined there is no such thing as a baseline healthy microbiome. Yeah. And that was one of the goals of this project that was started in 2007 was that to establish a baseline microbiome, like they didn't know what one looked like. They knew that people had tons of bacteria and protozoa and viruses all over us and in us. But what is that supposed to look like? And when you figure out what it's supposed to look like,

then you can figure out what an unhealthy one looks like. And then possibly how to correct that by adjusting this microbial ecosystem back to a baseline. But I'm not surprised that they found that there isn't a baseline. That is just too different. And that doesn't mean that they can't like learn a lot and help us out a lot. What they're basically saying is you take a dozen completely healthy people and their microbiomes are going to be completely different still. Yeah. And there was one huge revolution in the study of bacterial or microbial life that made this project possible. Same with the human genome, but much more for this. It's called metagenomics. And prior to the advent of metagenomics, if you wanted to study bacteria,

you had to find a bacteria that could be replicated, cloned in a laboratory setting. And this accounted for just a very, very small fraction of the number of microbes out there. What's more, so not only did you not have a representative sample, but you also didn't have any kind of anything less than an artificial setting. So even if you did get these microbes, if you could replicate them in the lab, they weren't going to behave the way they would in their natural setting, like on your body. So what metagenomics did was you can now take like a representative sample, say like a clump of soil or a swab of somebody's ear fold and get all of the microbes in there and then basically just do this rough scan of them, separate all the

DNA out, add these enzymes that go and clip coherent fragments of this DNA out. And then you take it and you put it into what's called a model organism. And that model organism starts to replicate as cells. And then each cell displays a certain characteristic associated with a different microbe. So all of a sudden, you can start studying the different cells and say, oh, well, this has to do with this microbe. And this means that this protozoa is present and so on and so forth. And now you can get a truly representative sample of what's in a microbiome. And without metagenomics, none of this would be possible. But now we're starting to find all sorts of new, not just information, but even new species of bacteria and protozoa and fungi

from the study of this stuff. Which is a great thing. It is a great thing. And we'll explain why it's a great thing right after this break. Hey, friends, when you're staying at an Airbnb, you might be like me wondering, could my place be an Airbnb? And if it could, what could it earn? So I was pretty surprised to hear about Lisa in Manitoba, who got the idea to Airbnb, the backyard guest house of her childhood home. Now the extra income helps pay her mortgage. So yeah, you might not realize it, but you might have an Airbnb to find out what your place could be earning at Airbnb.ca. On the podcast, Hey Dude, the 90s called David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker

necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it. And now we're calling on all of our friends to come back and relive it. It's a podcast packed with interviews, co stars, friends, and nonstop references to the best decade ever. Do you remember going to blockbuster? Do you remember Nintendo 64? Do you remember getting frosted tips? Was that a cereal? No, it was hair. Do you remember AOL instant messenger and the dial-up sound like poltergeist? So leave a code on your best friend's beeper, because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge from your

Game Boy, blowing on it and popping it back in as we take you back to the 90s. Listen to Hey Dude, the 90s called on the iHeart Radio app, Apple podcasts, or wherever you get your podcasts. Okay, so we're back. We are back. And we were talking about the microbiome project, which is being rolled out in phases, the first of which obviously is to get as many of those samples via this new technology, and basically just get a big reference set, like throw them out on the table like a crawfish boil. In the hopes of establishing that baseline? Well, not just a baseline, just basically cataloging everything with the ultimate goal of seeing what this means to our body and how these different things interact.

So they put the word out on the street. The NIH said, Hey, we need some volunteers. Do you think you're a very healthy person? If so, come volunteer. And 600 people who consider themselves very healthy showed up and said, I'm a healthy person. Yeah, and they were dismayed to learn that half of them weren't healthy. Yeah, apparently, like, yeah, over half were rejected outright. Yeah, and that doesn't mean they're like, super unhealthy. It just means for the purposes of this. They needed the healthiest of the healthy people. And I read that even still of the ones that were accepted, the 242 that made the cut, 85% of those people still had to have periodontal disease and cavities treated first. And then basically, they had to be treated for that stuff. And then

they were deemed fully healthy. But that's how the level of health they needed for this study or that they wanted for it. Yeah, and it surprised me, they only got subjects from two cities. I thought it would have been like spread out, but Houston, Texas and St. Louis, Missouri are where the final subjects came from. And they haven't been, and they were all white, too. Oh, really? They were white men and women aged 18 to 40, I believe. And they were in the, they were the picture of perfect health after the dentists got finished with them. Why all white people, I wonder. I don't know, but it's not that this has been, that the human microbiome project has been criticized for it. It's more just been like,

so you guys got a swab of just these, just a small fragment of humanity. Yeah, maybe that's the starting point. Right. Well, yes. Because they can't include like every ethnic group in race when you're just starting out. Right. Okay. But I mean, it is surprising that they just went with Caucasian only. Okay. So they finally get these healthy people, a couple of hundred scientists, 80 different institutions. It's a big group thing. It's not just like one university that's running the show. Budget of about 170 million bucks to start out with and a bunch of cotton swabs. Yeah, lots of them. Over 11,000 cotton swabs. Generic cotton swabs.

Yeah, right. They swabbed each man in 15 locations. Yeah. Women in 18 locations, three of the locations were in the vagina. Men don't have vaginas. They don't, but men have ears and armpits and- Elbow folds. Yeah, mouths. Yeah. So they're up your nose. Stool. Stool samples. Yeah. They're getting as, you know, they're swabbing all the moist places. Right. And yeah, that's exactly right. Not just moist places, but I think that's where you're going to find the gold. Sure. You know. Yeah. Well, no, it's true. Like your forearm actually is typically pretty dry. Yeah.

But it has one of the most diverse array of bacterial species in your whole microbiome. Yeah. You have about an average of 43. Yeah. And people, when you hear this, don't think that didn't get the reaction I was expecting. Well, that seemed low to me. Yeah, I guess. Because I'm used to hearing like thousands. Thousands of bacteria, not necessarily species. Yeah, that's true. Although I think the mouth is going to top that from what I read. Remember, I said like that it's like up to 5,000 species? Oh, I believe it. Yeah. But I think one of our goals here and the goal of scientists is to stop people from

like changing the tide of how you even think about this stuff. So when you hear that, all the bacteria in your mouth and under your armpit, don't think gross. Think awesome. Well, yeah. For the most part. Yeah. You know. So the project, I guess, is still very much in its nascent stages, Chuck. Basically, they did the project itself. Yeah, they did the initial leg work and then they did the second phase, which is sequencing these things, which again, like I just painted the broadest picture of metagenomic sequencing. Yeah. It is one of the most involved, insane, complex processes I've ever like tried to understand. It's more complex than the breathalyzer. Remember that? It used like

kryptonite somehow? Yeah. That was very surprising. Yeah. If you don't know what we're talking about, go listen to our breathalyzers episode. It was really, those are complicated machines. Yeah. I thought there were fairies inside the little box that just smells like beer. Yeah. Metagenomics is better to just kind of understand it like little fairies performing magic than to really dive into it. But the point is this project, they have all this data now. Now, they have to sort through it. They have the problem of big data. It's just an overwhelming amount of data. Like trillions of bytes of data. 3.5 trillion bytes of data, which is about a thousand times more than the human genome project. At first, you're like, wait, that doesn't make

sense. We're talking about bacteria. And you go, oh yeah, that's right. We have about 100 to 200 times the genes in our microbiome than we do in just the human genome. So yeah, that's a lot of data. And now they're starting to figure out how to sort through it. All right. So I guess after this break, we can talk about some of the things we have learned thus far. Hey, everybody, when you're staying at an Airbnb, you might be like me wondering, could my place be an Airbnb? And if it could, what could it earn? So I was pretty surprised to hear about Lauren and Nova Scotia who realized she could Airbnb her cozy backyard treehouse and the extra income helps cover her bills and pays for her travel. So yeah, you might not realize it, but you might have an Airbnb too. Find out

what your place could be earning at airbnb.ca slash host on the podcast. Hey, dude, the 90s called David Lasher and Christine Taylor stars of the cult classic show. Hey, dude, bring you back to the days of slip dresses and choker necklaces. We're going to use Hey, dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it. And now we're calling on all of our friends to come back and we live it. It's a podcast packed with interviews, co stars, friends and nonstop references to the best decade ever. Do you remember going to blockbuster? Do you remember Nintendo 64? Do you remember getting frosted tips? Was that a cereal? No, it was hair. Do you remember AOL instant messenger and the dial up sound like poltergeist? So leave

a code on your best friends beeper because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge from your Game Boy blowing on it and popping it back in as we take you back to the 90s. Listen to Hey, dude, the 90s called on the I heart radio app, Apple podcasts or wherever you get your podcasts. Okay, we're back. All right, so now I guess we can talk about some of these great findings, some of the newest findings. In the last, what year is it? Well, they started in 2007 and it seems like the first crop of like amazing stuff started in about 2012. Yeah, so after they had categorized things and got like thrown all the crawfish out on the table. Right, the corn. Yeah, the little corn's good. Have you

ever done that? I've had that before. Yeah, it's good stuff. Yeah, it's fun. Go to a big party. There's a place in on Buford Highway called the Crawfish Shack. I've heard of that, but I haven't been. Do they do it like that? Do they just dump it on the table? It's all picnic tables. No, it's in like bowls and stuff like that, but it's all picnic tables inside. And just huge rolls of paper towels and it's dude, that place is so good. Yeah, I guess you can't do that as a restaurant, but if you go to a true crawfish boil at someone's home, you have the picnic table covered with the plastic thing and you just dump it on the table and everyone just stands around like a bunch of animals, getting drunk and eating like sucking

the heads of crawfish. My family used to do something similar to that when I was little in Toledo. My dad called it garbage pail stew. Yeah. Are you familiar? Is it like all the leftovers? No, it's like you use a trash can to make it. Oh, never heard of it. Over like a flame. Okay. And obviously you use a new trash can, like a brand new one. So I guess when dad got a new trash can, we would have garbage pails too. Anyway, a metal trash can? It was, yes, it was more like a, no, the plastic just added this new. No, I'm just trying to like a one big large ones. One of the old timey ones. What kind of flame you got in your house? I don't remember what he cooked it on. Interesting. I don't, like in my mind's eye,

I can't look down. I can just see, I can just see the kind of the top of it. But anyway, it was like a Yankee Northern Midwestern version of it. So there was like lots of cabbage in it. Oh, sure. And like kielbasa and stuff like that. But it was essentially the same thing. Yeah. And you would eat it on like newspaper. I can't wait to get emails from people who are like, we did that same thing. I've looked around. I've never seen it since. I'm sure that, yeah, that sounds like a thing that. Or. Although your dad is very unique person. Insane is the way to put it. All right. So back to the project and the findings. One of the things they've learned is that periodontists, this gum disease, some bacteria are elevated

if you have periodontists. So that's going to give you a little insight to maybe how you can better take care of your mouth. What kind of bacteria you need in there? What kind you don't? Yeah, exactly. And like, for example, streptococcus mutans is responsible for cavities. So you want to take care of your streptococcus mutans. Mutans. The thing is, Chuck, that reading this made me wonder, like, are we going to go the other direction now where it's like, we understand that you can't just use antibiotics to get rid of everything. Yeah. But if we identify bacteria that's like, oh, well, that one gives you cavities. Let's get rid of all of that and find some sort of medicine that just gets rid of that. It could make things even

worse in a whole other direction. Like, one thing that I figured out from this is that the microbiome appears to exist in balance. Like, stuff that should make us sick, E. coli, kinds of strep, staff, that kind of thing. Like, it exists on a healthy person's microbiome and it's just hanging out there. So it doesn't mean that they're inherently disease-causing for us, or that they're inevitably disease-causing. Apparently, if they exist in harmony with their neighbors, that's the way it's supposed to be. And we can't just root out just ones that make us sick and get rid of those because I think it'll have repercussions. But we might have a future where, instead of an antibiotic, you actually take a bacteria that will attack the other bacteria,

the bad stuff. Right. Or you can... Right, exactly. Like, as long as we're not intervening and going after a specific bacteria, if we can aid the bacteria, like you say, that will fight it naturally, like by eating some sort of sugary paste, you know? Or probiotics. I mean, that's what that is, right? Yeah. And they're all the rage. I mean, that's an issue that's being examined in more detailed thanks to the microbiome. Like, do probiotics work? Yeah. And apparently, the jury's still out. Yeah, well, sure. Like, in theory, they should work. Yeah. But it depends on, you know, whether these things are actually colonizing your guts. And also, I have the impression that it's like you don't really know what you're doing when you're adding like all these new people to the

neighborhood. Yeah. And because everyone's microbiome is so different, some one probiotic for one person might be great. And for another person might not do anything or make things worse. I don't know. Yeah. Which is another goal of the Human Microbiome Project, that if we start to understand, you know, what a colony, maybe there's not a normal colony for everybody, but what an individual's normal colony looks like, then you can take blood or samples and make adjustments based specifically on what you need right there. It could be the end of pharmaceutical drugs conceivably. I know they're doing a lot of research into how your gut bacteria affects obesity in your weight. They have found obese mice and transferred microbes from their gut

into skinny mice. And the skinny mice gained weight. And there's just type in gut bacteria and obesity. And there are a lot of studies going on now, thinking that maybe correcting your gut bacteria could actually help you help your metabolism, you know, straighten out. Right. Like they think the bacteria itself directly informs how the body uses or stores energy. Yeah. Yeah. The one that blew me away was there's a type of bacteria that helps, that helps break down milk in humans. Oh, yeah. And typically it's in the gut. But as a woman advances in pregnancy, some of it moves down to the vagina. Yeah. And at first, the researchers who found this were like, well, what's the deal with that? And then they figured it out. They

think when a baby is born and it passes through the vagina, it basically becomes covered in this bacteria, ingests some of it, and that bacteria goes down and colonizes the baby's guts and prepares it almost immediately to start breaking down breast milk. Yeah. Evidently, brand new babies are just sponges and like they're experimenting with cesarean sections to just swab. Like after you have the cesarean section, you bring the baby out, swab it with vaginal mucus. Yeah. And basically, it just soaks right into the skin and maybe have the same result. Right. Or swab their mouth or something like that. Yeah. Another way, and I guess that's kind of related to is with the immune system. Apparently, the microbiome acts as kind of like a teacher to the early immune system and

says like, hey, these are the good ones. These are the bad ones. Why don't you go ahead and produce some T killer cells or killer T cells, but not too many. And we'll just go ahead and keep the homeostasis going. And they basically like teach a young immune system how to operate at an optimal level. And they found that by engineering mice that are like totally germ free, their immune systems have a tendency to go crazy. Like they'll become inflamed in the presence of what are say non-harmful fungi. Yeah. They'll become so inflamed that they'll damage the surrounding tissue. Or they'll have like irritable bowel syndrome or Crohn's disease, they think also is a flux state of the microbiome in the gut. So apparently, it directly impacts the immune system

as well, which my friend lends a lot of weight to the hygiene hypothesis. Yeah. That's basically the notion that here in the West and even in developing countries now, children are seeing such a decrease in infection when they're kids that when they grow up, they have an increased number of allergies and maybe autoimmune issues. Yeah. And you kind of see it playing out, you know. Right. Like it's a real thing. Like if you're slathering your child with Purell, you're not doing them any favors. Right. So they may have asthma later on because of that. Exactly. And they are becoming, they're coming to think that it's because of the just a stunted growth of the microbiome. Yeah. And I think they've found now even they think they have a direct link between

your gut bacteria and allergies. So if you get hay fever, it may be because of your gut bacteria. Right. And it makes just utter and complete sense too. Yeah. Like your body has been exposed to these things early on, learned that they're not harmful and no longer produces antibodies as a result of their presence. Yeah. Because that's all an allergy is. It's a case of mistaken identity. Yeah. Your immune system thinks that pollen or something is a harmful for an invader and launches your immune response. Pretty cool. Some of the other interesting things they found so far is that there wasn't a single microbe that everyone had in the study. Yeah. Which is pretty interesting. And that microbes are most similar on the same site of different people. So like you and I

have more similar microbes in our armpit, even though we're different people. Right. Then you, your microbes in your armpit has to do with your belly button. Yeah. Ours are more similar than the ones in different places on your body. Yeah. That's pretty neat. And different microbes can do completely different things. Like the way you digest food might use one microbe and I might use another or that same microbe might have a completely different function in you than it does in me. Right. So it's so personalized. It's like, it feels like the beginning of hyper-personalized medicine. I think it is. In the future. I definitely think it is. I think it's also the beginning of a kinder, gentler approach to treating disease. Yeah. All disease.

Like it's entirely possible, especially if you take a brain-based view of mental illness. It's possible that every bit of disease can be cured by understanding the microbiome. Even cancer apparently, they found from this that some types of cancer manage to cloak themselves by taking like a resin or residue from certain types of bacteria and basically sneaking past your immune system and going and lodging itself into cells and hijacking them and creating tumors. But it cloaks itself by getting buddy, buddy with certain kinds of bacteria. Cancer is a jerk. Yes. Cancer is a big time jerk. We've kind of covered it here and there, but I could see more specific cancer podcasts in our future. Sure. You know what? Yeah.

So like so far we've done two that specifically got into the microbiome, but we've never done like any microbiome one. Yeah. So I think we should come back like a year from now and even more stuff is out and do like the microbiome. Yeah. It seems like they're making breakthroughs at a pretty rapid pace. Yes. So in a year, they might, everyone might be skinny. Yeah. Because of the microbiome pill. Have you seen a picture of like an obese mouse next to like a skinny or normal sized mouse? Yeah. It's pretty depressing. It is. Sad mouse. Okay. So I will see you here at the end of next April. God willing. For the microbiome one. Deal. All right. If you want to learn more about the human microbiome, you can type that, well, those words into the search

bar at howstuffworks.com. And I said howstuffworks.com, so it's time for the listener mail. Josh, I'm going to call this a response from a creationist. Oh, okay. We got a few of these. Yeah. Hey, guys, listen to your podcast on natural selection and really enjoyed it. I'm a biologist who is a Christian and creationist. A natural selection is not what we disagree on. And when I say we, I mean most creationist, but of course with every group there are outliers. We agree with micro evolution, changes that occur within the species, not macro evolution, species developed into a completely different species, which is what most people tend to associate with evolution. The only major differences between creationists and evolutionists

is that we believe the earth is between six and 10,000 years old. And again, excluding the outliers and that all organisms were created in their basic form by our God. For example, we believe that everyone came from Adam and Eve who through methods of natural selection evolved into the many nationalities we have today. Same thing with animals. We believe that a small number of species were created by our God and all the forms we have today evolved through natural selection. So the only main difference that we have with evolutionists is the ultimate origin of species, the areas of evolution that we can see clearly occurring in front of our eyes. We agree with, it's the areas that evolutionists theorize about that we don't agree with. So while there are

differences between creationism and evolution, they're actually more similarities. And that is Eric from South Bend, Indiana. Thanks a lot, Eric. Very salient point. Yeah, biologist. Yeah, I love it when experts come out of the woodwork, especially when they're experts with a twist. Yes, and we love being refuted and refuting and reading refutations and we'll always read these things. Refutation life. That's right. If you want to refute something we've said or agree with us or whatever, if you just want to get in touch about anything, you can tweet to us at SYSK podcast. You can join us on facebook.com slash stuff you should know. We're on Pinterest or on Instagram. And if you want to send an email to Chuck, Jerry, and me, you can address it to stuffpodcast.howstuffworks.com.

Stuff you should know is a production of iHeartRadio's How Stuff Works. For more podcasts from iHeartRadio, visit the iHeartRadio app. Apple podcasts are wherever you listen to your favorite shows. On the podcast, Hey Dude, the 90s called David Lacher and Christine Taylor, stars of the cult classic show Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it and now we're calling on all of our friends to come back and relive it. Listen to Hey Dude, the 90s called on the iHeartRadio app, Apple podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart

podcast, Frosted Tips with Lance Bass. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help and a different hot sexy teen crush boy bander each week to guide you through life. Tell everybody, yeah, everybody about my new podcast and make sure to listen. So we'll never, ever have to say bye, bye, bye. Listen to Frosted Tips with Lance Bass on the iHeartRadio app, Apple podcasts, or wherever you listen to podcasts.