Daniel and Kelly’s Extraordinary Universe - Do microbes help or hurt you? (featuring Katrine Whiteson)

Episode Date: May 20, 2025

Daniel and Kelly talk to Katrine Whiteson (a Whiteson Prize laureate) about the complex relationship between humans and microbesSee omnystudio.com/listener for privacy information.

This is an I-Heart podcast. I'm Dr. Scott Barry Kaufman, host of the psychology podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy which is more effortful to use unless you think there's a good outcome. Avoidance is easier. Ignoring is easier. Denials easier.

Complex problem solving takes effort. Listen to the psychology podcast on the. iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. On the new podcast, America's Crime Lab, every case has a story to tell. And the DNA holds the truth. He never thought he was going to get caught.

And I just looked at my computer screen. I was just like, ah, gotcha. This technology's already solving so many cases. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. It's important that we just reassure people that they're not alone, and there is help out there. The Good Stuff podcast, Season 2, takes a deep look into One Tribe Foundation, a non-profit fighting suicide in the veteran community. September is National Suicide Prevention Month, so join host Jacob and Ashley Schick as they bring you to the front lines of One Tribe's mission. One Tribe, save my life twice.

Welcome to Season 2 of The Good Stuff. Listen to the Good Stuff podcast on the Iheart Radio app, Apple Podcasts, or wherever you get your podcast. Let's start with a quick puzzle. The answer is Ken Jennings' appearance on The Puzzler with A.J. Jacobs. The question is, what is the most entertaining listening experience in podcast land? Jeopardy-truthers believe in... I guess they would be Kenspiracy theorists. That's right.

They give you the answers, and you still blew it. The Puzzler. Listen on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Nobody likes getting colonized by microbial invaders. Those little guys swimming around inside you, messing up your body's normal function, hijacking yourselves to make more themselves. Meanwhile, giving you headaches or sniffles or stomach. pains or even worse. No, we want them out. We take medicine to kill them or we wait for our immune

system to hunt them down and root them out, leaving us with pure, unpolluted human bits, right? Not really. Actually, the truth about our relationship with microbes is much more complex. They not only fight on our side sometimes. Most of the time, we can't even tell who is on which side or if there are even sides. Maybe it's more like a big microbial economy than a black and white battle. Today on the podcast, we're going to dig into the life of microbes and the role they play in keeping us healthy and sick. Do they help us? Do they hurt us? Or is the answer, as always, it depends. A word to today's parents, today's episode is getting a little gooey. We can't talk about microbes without talking about poo. It's always a conversational risk when talking to biologists.

So keep that in mind if you're playing this episode with your little ones. I vote, let them listen. There's pooher in knowledge. See what I did there? Either way, welcome to Dan Daniel and Kelly's extraordinary microbial universe. Hello, I'm Kelly Weiner-Smith. I study parasites in space, and today we are talking about one of my favorite topics as a biologist, which is to say microbes and poop. Hi, I'm Daniel. I'm a particle physicist, and I'm a particle physicist, and I'm a particle physicist, and I'm I have poop in my freezer.

Oh, oh, that's a little too much. But all right, so what is the most unpleasant microbe related thing that's ever happened to you? You want to hear about every time I had diarrhea? Maybe the one worst time is what I was thinking. I guess, no, maybe not. Nobody wants to hear about that. Never mind.

I'm backing off. For me, it was an infection that wasn't healing and that was unpleasant. We should go in a different direction. What else should I ask? Here's my question for you. What is your favorite thing to consume that increases the diversity of your microbiome, however temporarily? Well, as you'll hear in our conversation with Katrina in a minute, we are big fans of beans in the whites and household. And so we're even members of the Rancho Gordo Bean Club, which means we have mail to us every few weeks, a box of heirloom beans.

And so we have all sorts of crazy beans. And basically we have beans at every meal. Wow. So you must have like the best bean recipes. Can you send some to me? Absolutely. Yeah, we'll share some with you. Because I got to say, after this conversation with Katrina, I am starting to think about how beans can be incorporated into every one of our dinners, at least. We put lentils on everything. They're in salad. They're in everything. They're fantastic. Yeah, we're big fans of beans. And our son loves beans, too, which is a great outcome.

You didn't mention your daughter. Does she not love beans? She's not yet on the bean wagon. Yep. You know, it's hard to get kids on the bean wagon, I imagine. Yeah. Well, you know, with lots of foods, you can start with like the easier version, you know. Like if you're going to start drinking coffee, you put milk and sugar in it. I'm not quite sure what the easy way is with beans. Maybe put lots of cheese on top or something. At tacos.

It's got to be tacos. Tacos, yeah, exactly. Anyway, today we are talking about really fun and really important topics. What's going on inside our bodies and on our skin about all those critters that are living with us or who are part of us. And you asked our listeners a question to gauge how subtly they understand the importance of bacteria in our body. body. So you ask them, do microbes hurt you or keep you healthy? And here's what they had to say. Microbes in your body are what allow you to function at all. So yeah, they're helpful. Although some kinds of microbes are bad for you and they will hurt you. Both. There are good microbes

and bad microbes. Providing the microbes in your body are kept under control in their number and their type, they can definitely help you. But if you get introduced microbes or the microbes get to a critical number, then they can also cause harm. Like most questions in biology, the answer is it depends. For example, your digestive system doesn't work without microbes, but if you have too many of the wrong ones, then it doesn't work at all. We couldn't live without microbes in our body. I'm on to you now with your deliberately vague questions. So microbes in the body, I think what you wanted me to say was in the body but not in the bloodstream. However, I think the research has changed on that. So I actually think you do have microbes in the bloodstream now, but by and large,

yeah, they are good for you. I read somewhere that our bodies, our whole ecosystems. So, So I would say that on the whole, the microbes are beneficial to us. They do both. They help you, and they can hurt you if they metastasize turn to cancer. Microbes in our body are good and help, but there might also be bad microbes that you could get that would make you sick. They can help or hurt or neither or either one depending on where it happens to be. I think the general rule of thumb is that the microbes that are in your body are there to help you, whereas the microbes that are trying to get into your body from the outside are the ones you've got to worry about.

I believe the great majority of them are benign and useful microbes compared to the rare unwanted intruders. Help, absolutely help. I can barely distinguish myself from my microbes. Finally, a question I can actually answer as a nurse. Mars. Microbes in the body can be harmful or beneficial. It depends on the type of microbe, the quantity of that microbe, and the location of that microbe. Both because some are bad for your body like germs and some are good for your body like good bacteria. There are 40 trillion microbes in your body compared to 38 trillion human body cells in your body. And the majority of the microbes are there to make you feel better and then every once in a while when the balance is out

of whack they get into stuff they're not supposed to and cause us a little bit of damage but hey what are friends for microbes span the gamut from being critical for functioning to being lethal we might not exist without microbes it's something like 10 times more microbes than human cells in the body um they help with digestion and glucose metabolism, help absorb nutrients in the body. Classic science answer, it depends. Oh, this is a false dichotomy. Microbes both hurt and help you.

I think microbes in our body are the part of our body. These are great answers. Thank you very much to our list of volunteers. And remember, you can join them at any time. Just write to us to questions at danielandkelly.org. And we will hit you up next time. Kelly, what did you think of these answers? I like, I can barely distinguish myself from my microbes that made me smile.

I wanted to learn more about the cancer and bacteria link. I don't know too much about that. Yeah, what about you? What was your favorite answer? I like the person who said that they're on to us with our deliberately vague questions. This whole thing is some kind of scheme. Yeah, I thought these were great. And they showed that people have already a pretty nuanced understanding of microbes.

They're not just pathogens. They're part of who we are and how we live. and all of our futures. All right, well, I think it's time for us to dig in with the interview with our special guest today. So it's my pleasure to welcome back to the podcast, Katrina Whiteson. She's the senior editor of the Whiteson Science Report, a quarterly journal, and she's the current holder of the Whiteson Endowed Fellowship for actual experimental science,

not just computer stuff. Whoa. Welcome to the pod. I don't think you guys understand what a big concession that was. There have been times at UC Irvine where there were three Whiteson Labs. There was Daniel Whiteson, who you all know and love. Shimon Weitzen, his brother, who is a computer science professor at Oxford, but came and did a sabbatical here.

And then there was the actual Whiteson Lab, Katrina Weitzen, where there's like a physical lab and there's people in there growing microbes and glassware being autoclaved and stuff like that. It wasn't just like in the cloud, you know? Well, we're not here today to debate the philosophical question of whether stuff on the computer is actual science or not that's just me trying to butter you up to the episode i think we should bring you back for that debate though i know that what daniel does is real science i don't mean that i'm just i'm just enjoying the joke you know i'm just glad to get that on the air while we have

that recording oh boy so today we've invited you on the podcast because we're talking about microbes and microbes in the body and whether they help you when they hurt you what their role is are they part of us. Are they our friend? Are they our enemy? Are they a friend of me? How does it all work? And this is your area of expertise. So we're very happy to talk to you about it. But first, let's get people acquainted and make sure everybody is talking about the same thing. Like, when I say microbe, what does that mean to you? Well, microbes refer to life forms that are too small to see with the naked eye. But it can refer to like lots of different branches of the tree of life. So microbes can be viruses, which we even debate whether they're alive or not, but they're

definitely the most biologically diverse entity on the planet. So viruses, bacteria, fungi like yeast, other eukaryotic parasites, like nightmarish ones that cause diarrhea. But most microbes are not pathogens. Even though most of what you hear about microbes are pathogens, most microbes actually are living their lives. Their goal is never to cause disease. They're out for themselves, you know? They have goals? You mean like if you talk to them, they'd have like hopes and dreams. Well, I mean, I think all life forms have a basic goal of reproduction, whether they're like thinking about it or not. Could you give us a bit of our history on the thinking about this? Like, did we always think it was bad to have microbes in our gut? Have we kind

of gone back and forth on thinking they're good or bad? Yeah, I mean, definitely. Well, the first time we ever even saw a microbe was when Van Lohenhoek ground his own microscopes. He was a draper in the Netherlands, and he was grinding his own microbe. in order to look at the threads at the edge of the curtains he was making. But then for fun, he just took a piece of dental plaque, like a glop out of his mouth, and looked at it, and he saw the little microbes jumping around. And he drew pictures of them. He called them animal cules.

That's the first time we saw a microbe. At that point, I think, our thinking was pretty neutral. I mean, it took us a couple centuries to even realize that, like, washing hands was a good idea to prevent disease. So, yeah, it was pretty neutral for a while. But then I'd say by the 20th century, once cock postulates and we understood that microbes caused disease, then I think we were just expecting every time we turned a corner and discovered a new microbe that it was causing disease. And you might have heard of like bubble boy or in the 1950s when we first developed

notabiotic cultivation. We at that time thought, like, wouldn't it be great if we could all be sterile? We really didn't imagine that the microbes were doing too much positive, with a few exceptions. Like there were people who appreciated probiotics around the year 1900. We go back, I want to understand what is notobiotics and who is the bubble boy? Great. Notobiotics refers to cultivating animals in a intentional community of microbes. It doesn't actually have to mean sterile.

It can often mean like intentionally cultivating, say a mouse with like 10 known microbes and then like learning exactly how those microbes affect immune development and all other kinds of health outcomes. So notobiotics are a really important tool in microbiome science where we can intentionally cultivate mice or zebrafish or like pick your model animal of choice. We can't really do that with people though. With this exception of Bubble Boy, who was a boy who had severe immune deficiency and I mean kind of brilliantly considering the technology available at the time, his medical community, the doctors around him figured out how to keep him in essentially sterile conditions, like in a, plastic bubble with oxygen pumped in so that he was never exposed to microbes that would quickly kill him. There's a movie about it too. So that's pretty rare to have a human growing up with

that little microbial exposure. But at that time, we thought like, oh, the more antibiotics, the more better, just like pop them down. It'll probably help you. There was not really a feeling of loss that by taking antibiotics, you were destroying something. When I feel like since then, we've gone in the opposite direction where whenever you're listening to a podcast. You get advertisements about bacteria that are so good for you. And have we sort of gone in the opposite direction? Are we finding a happy medium? That's a good question. I feel like the ads you hear are sometimes coming from the $80 billion probiotic industry, which is not really resting upon too much evidence, to be honest. And so the kinds of things you hear in those ads are

often not all that close to reality. So I guess it depends a little bit about which parts you're hearing about. I think the message that we shouldn't just pop antibiotics without any concern for the damage they can cause, I feel like that has gotten much better. So yeah, I think we have come to appreciate that taking antibiotics has a consequence that's not only positive. Although, keep in mind that 80% of the antibiotics used in the United States, at least, are in agriculture. So our own human consumption can only have so much impact on avoiding the antibiotic resistance crisis. All right. So microbes are these little critters that are too small to see, which frankly feels to me like a little fuzzy. Like if I have terrible vision, are there some things that are microbes

to me? Like if I can't see cats, do they count as microbes? Because I've like barely bad eyesight. No. As usual, it's biology, so it's fuzzy. No, I mean, it's definitely like, you know, if I had a slide, I could give you some images of the scale bar and the sizes of viruses and bacteria. Like, your average bacterial cell is about 10 times smaller than your average eukaryotic cell. eukaryotic cells have a nucleus. Those are the kind of cells that make up our bodies. And there's also unicellular versions of them. But I mean, yeah, the point is just that they're tiny and they tend to be unicellular too. I mean, some dogs are tiny too. Around LA, the fit in people's purses microbial dogs. All right. Anyway, those dogs have like 4,000 times as many microbes in their

guts is what I'm saying, though. I mean, toy dogs are pretty small. Anyway, you're the expert on it. So I'll defer to you. And so you've walked us through this history where we learned about microbes. Some of them caused disease. But now we have a more nuanced take. So tell us, like, if microbes are part of us, where on the body do they live? Where can I find microbes in my body? I mean, you can find microbes literally everywhere, whether it's your body or not.

And so that's actually a challenge. Sometimes I start my talks out with this challenge that, like, a key postulate of microbial ecology is that nothing is sterile. And then I try to think of maybe exceptions to that, like places where life really can't be sustained. But I mean, you could just check out any environment, deep sea, ocean vents, hot springs, you know, the outside of a spaceship. Like, what about uranus? Is urinus sterile? Wow. Well, that depends a bit on the meaning. Answer it in however you like. Well, I think there are places that have very, very low microbial load and some materials

that can't really sustain microbial life so well, like maybe glass, for example. But on average, you know, on your body, which was your question, we have really, really dense microbial colonization in our gut. Those are mostly microbes that can't survive with oxygen. Like they're called anaerobes, so they live without oxygen. Most of the microbes in your gut are anaerobes, which I just think is amazing because we obviously live in a world with oxygen, so it's kind of crazy how all these anorobes colonize our bodies. We're reverse bubble boys for the bacteria in our guts. Yeah, exactly. Even your teeth have really strict anorobes growing on them. So your oral cavity is super, super, super densely

colonized with microbes. Like the number of microbes per density is about the same in your oral cavity and in your gut and like in a soil sample where they're famous for being teeming with microbes. And in your oral cavity, there's just gradients of microbes that gobble up the oxygen at the surface so that shields the ones underneath so that the anaerobes can survive. Why do you say oral cavity instead of mouth? Well, I mean, mouth is probably a better choice. I see what you're saying. But I guess I just got so used to writing papers about oral microbiomes and oral cavities. And like in the human microbiome project, there were 17 sampling sites in the oral cavity. There's symmetry, like your two back top teeth,

on each side of your mouth have more similar microbial communities compared to ones closer to the surface having to do with like nutrient access. And so I think I'm just thinking about that when I say it. We've gotten a little bit farther away from my favorite topic. So first I want to point out that Daniel was the first one to mention poop and butts in this episode. I win. I win. You can't always blame the biologist. But I've been dying to ask you. So I heard that our bodies have so many microbes that we have. more microbes in our body than we do cells. But then I heard that the balance of power changes immediately following a bowel movement because there's so many bacteria in our feces.

What is the truth, Katrina? I have to know. Well, that's an awesome question. And it's been a real topic of debate. And it's funny because it's like the intro slide to every microbiome talk for about 10 years was all about how there's 10 times as many microbial cells as human cells and an average human body. But then we redid our back of the envelope calculations. So now we call it front of the envelope and now the ratio is estimated to be more like one to one. But like both the numerator and the denominator are like highly in flux here. So I wouldn't swear the life of my children on these calculations or anything like that because it's really good to know. Wow. But like even just estimating the number of cells in a human body.

Wait, sorry, are there science conversations that you have that I'm not in where you are swearing the life of our children? No, definitely not. I mean, I've got to wonder now, but I hear this. Daniel, I feel like you're often on the show talking about dangerous situations you'd put the kids in for the sake of physics. I don't feel like you have to be high and mighty about this. I'm mostly talking about your kids, Kelly.

Oh. Oh, wow. Interesting. I'm sending my kids to their grandparents' house when you guys come to visit next week. That's good. All right. So, Kachini, you're telling us there's a lot of uncertainty. We don't really even know whether there are more human or microbial cells in our bodies.

I'd say that balance is closer to roughly even. And I agree that when you have a bowel movement, the balance would shift because you would lose a lot of microbial cells every time. Depending how much fiber you eat and if you have really big bowel movements or not. But no matter what, despite the number of cells, what we can always say is that the diversity, of metabolisms in our body is heavily weighted towards the microbes because human cells can only pull off like a pretty small number of metabolisms, like the number of types of genes is pretty small in comparison to the number of types of genes that microbes carry. Each microbe can live in a totally different niche, like there's microbes that live with no oxygen or microbes that

can live with a little bit of oxygen, and they each carry very unique genes for breaking down all kinds of molecules. So like our metabolomic diversity is unquestionably much more coming from our microbes than from our human cells. All right. So I feel like we're transitioning from talking about individual microbes to talking about like communities of microbes. And you're telling us these live here and those live there. And you hear the word all the time these days, the microbiome. Yeah. It's a microbiome, just a description of like the microbial communities. Yes, exactly. So a microbiome is a community of the microbes we just defined. in a particular environment.

So the microbiome definition includes what the environment is. So like the kind of microbes that live in your gut where there's not very much oxygen is very different than the kind of microbes that live at the surface of the ocean where photosynthesis is a big deal. So it's about what type of life is sustained in that environment. So if I see like a bunch of ladies in L.A.

with 100 tiny little dogs that are so small that I can't see them, so those are all microbes and together they make a little microbiome. I mean, I can't really just say yes to that. And if you can't see the dogs, that means they're in your imagination. So then... They're philosophical dogs.

You need some evidence to support your claims. I thought you were a scientist. Wow. I just do computer stuff, actually. It's good to know that next time Daniel and I have a conversation like this, it's okay to just say, I'm not humoring that. Move on. Oh, no.

In theory, I see what you're saying. And like, only Los Angeles would support 100 people with microscopically tiny dogs. So that's kind of special to that environment. I see your point. So then I want to connect it back to something you said earlier. You were talking about the kinds of microbes that live in different parts of our bodies. Do we have, like, one microbiome, like one community of microbes? Or are there different communities of microbes that live, like, in my oral cavity and on my gut or on the tip of my nose?

Yeah. There's really big differences in the types of microbes that live. in your gut versus your oral cavity versus like the drier patches of your skin on your elbow versus the oilier patches of your skin in another part of your body like your armpits say and also super interesting most of our bodies on the skin we have a lot of diversity of bacteria but on our feet which are more moist we actually have more diversity of fungi and this is all in health anyway if we start talking about transplants which i imagine we will there's fecal transplants there's armpit transplants, there's ear microbiome transplants. And so getting a healthy community

of microbes going is really important to our health. But even defining health, of course, is really hard. Well, can we try to talk a little bit more then about what these microbes are doing for us? So you mentioned that a bunch of the metabolism that happens in our body is caused by bacteria. And that sounds like it could be helpful. So what are some things that our bacteria do for us? Oh, what a great question. So, I mean, to be honest, a lot of this is still unknown. So that's what's so fun about our field. I'd say most of the things the microbes are doing, we don't know what they are yet. But things that they do, for example, are they can break down fiber. So when you eat fiber in your diet, actually human metabolism can't handle that at all. But the anaerobes living in your gut, they're really

good at breaking down fiber. And another example that I love is the sugars in breast milk. They should actually be called fibers as well. So in breast milk, about 15% of the energy is in the form of sugars or fibers that human metabolisms just can't access at all, but the microbes can. And so this is a really important moment in human history, like what moment matters more than when a baby is born. Clearly, we wouldn't just throw 15% of the energy that's in breast milk down the drain unless it was really sustaining something important. And that 15% of the energy in the breast milk is sustaining specific microbes that can break down the breast milk sugars. And then when a diarrhealial pathogen comes through and tries to take up residence in a baby gut,

it doesn't have access to that secret nutrient source. And so a big protection mechanism for babies in parts of the world where diarrheal illness is still a really big deal, is if you're breastfed and you have those microbes that can break down the breast milk sugars, then when salmonella comes through is just kind of like cup paper, and those special microbes like bifidobacterias that can break down the breast milk sugars dominate the baby gut. That's probably how most baby guts were organized while they were breastfed through human history. So let me see if I understand, you're telling me that basically the first step in digestion, like I eat a bowl of beans. It's not that my human mechanisms get involved

and break the beans down, but like microbes are on the front line and they start the process breaking things down because I can't. The order of events there is a little different. Like, okay, so you're eating your beans, they get to your stomach. The stomach acid starts to break things down. Digestive enzymes come in from your pancreas and small intestine area. So actually the first chomp at most nutrients is coming from earlier steps in your digestive tract. And actually the microbial load is quite low. Like we do have microbes in our stomach, but at not very high density. And same with our small intestine. But by the time you get to the colon, so you need to eat foods that don't get absorbed quickly earlier in your digestive tract to give your microbes

access to them. So if you just eat white rice or processed foods, those get absorbed real quick in your stomach and small intestine. But if you eat things that take longer, then they get down to where the most dense community of microbes lives, and then you can give those microbes a chance to break down the fibers. I'm sure there's a question, but I just want to ask one quick follow-up about the baby thing, you're telling me that human mothers produce something that babies cannot digest without microbes in their guts, which means, of course, that we've been doing this for a long, long time, right? And microbes probably evolved with us, but how do babies get those microbes? Like, do they get them from the mom? Is it during the birth? Is it during

gestation? It happens after birth, but actually there's probably many opportunities. When something's really important. It's good to have a lot of ways for it to happen. And so it's not just only at birth. It could be at birth. But I would imagine that in a village or a community in human histories passed where there were a lot of young children that this would be passed between siblings and friends. I mean, you just need to be in an environment where that microbe exists. So it doesn't only have to be at the moment of birth. It could be at the moment of birth, but it could also be really at any time in the beginning of life. All right, well, that takes us all the way back into prehistory and the understanding of microbes.

We're going to take a break and we're going to come back and we're going to talk about the present and the future of microbes. You didn't have to audition? No, I didn't audition. I haven't audition in, like, over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We've got some of the biggest actors, musicians,

content creators, and culture shifters, sharing their real stories of failure and success. You were destined to be a start. We talk all about what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing vivras you've come to expect. And, of course, we'll explore deep.

deeper topics dealing with identity, struggles, and all the issues affecting our Latin community. You feel like you get a little whitewash because you have to do the code switching? I won't say whitewash because at the end of the day, you know, I'm me. But the whole pretending and code, you know, it takes a toll on you. Listen to the new season of Grasasas Come Again as part of My Cultura Podcast Network on the IHartRadio app, Apple Podcasts, or wherever you get your podcast. A foot washed up a shoe with some bones in it. They had no idea who it was. Almost everything was burned up pretty good from the fire that not a whole lot was salvageable. These are the coldest of cold cases, but everything is about to change.

Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. A small lab in Texas is cracking the code on DNA. Using new scientific tools, they're finding clues in evidence so tiny you might just miss it. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, gotcha. On America's Crime Lab, we'll learn about victims and survivors.

And you'll meet the team behind the scenes at Othrum, the Houston Lab that takes on the most hopeless cases, to finally solve the unsolvable. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Hey, sis, what if I could promise you you never had to listen to a condescending finance, Tell you how to manage your money again.

Welcome to Brown Ambition. This is the hard part when you pay down those credit cards. If you haven't gotten to the bottom of why you were racking up credit or turning to credit cards, you may just recreate the same problem a year from now. When you do feel like you are bleeding from these high interest rates, I would start shopping for a debt consolidation loan, starting with your local credit union, shopping around online, looking for some online lenders because they tend to have fewer fees and be more affordable. Listen, I am not here to judge. It is so expensive in these streets. I 100% can see

how in just a few months, you can have this much credit card debt when it weighs on you. It's really easy to just like stick your head in the sand. It's nice and dark in the sand. Even if it's scary, it's not going to go away just because you're avoiding it. And in fact, it may get even worse. For more judgment-free money advice, listen to Brown Ambition on the IHeart Radio app, Apple Podcast, or wherever you get your podcast. Your entire identity has been your beloved brother goes missing without a trace. You discover the depths of your mother's illness the way it has echoed and reverberated throughout your life impacting your very legacy. Hi, I'm Danny Shapiro, and these are just a few of the profound and powerful stories

I'll be mining on our 12th season of Family Secrets. With over 37 million downloads, we continue to be moved and inspired by our guests and their guests. courageously told stories. I can't wait to share 10 powerful new episodes with you, stories of tangled up identities, concealed truths, and the way in which family secrets almost always need to be told. I hope you'll join me and my extraordinary guests for this new season of Family Secrets. Listen to Family Secrets Season 12 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. And we're back.

And okay, Katrina, I have a question for you that I get asked a lot, and I would love to know what the answer should be. So I study parasites that manipulate the behavior of their hosts, and often people will say, okay, I've heard that our brains have nerves that go down to our stomach and that bacteria do things like release serotonin and dopamine that can communicate with our brains. So are our behaviors controlled by our microbiome? Can our microbiome be like, you need to eat more beans or something? So to what extent are our microbes influencing our behavior? Well, I mean, a lot for sure. There's definitely a very strong gut brain axis. And we've known that for a long time, even independent of the microbes.

We know that a lot of our nervous and immune system is in our gut. and so 90% of the serotonin in your body is produced in your gut, for example. And it's with the help of neuroendocrine cells in our guts, but those cells are being manipulated by the microbes. So there's a really strong connection between the dense community of microbes in our guts and all of the different types of cells lining our guts that are interacting with our nervous system. So there is a very strong gut-brain connection, no question. question, and there's so much interesting evidence, which is hard to sort through about how

if you improve your diet, you can improve symptoms of depression. Or if you meditate regularly, you can improve your inflammatory state and your microbiome composition. Where you're saying it goes both directions, not just microbes are influencing how we think, but your brain can control the microbes somehow? I mean, when you say it like that, it sounds fantastical, but I mean, I literally just watched Joe Handelsman give a talk last week about how people who were meditating regularly had improvements in their microbiome. And defining an improvement is a really hard thing to do in our field. So, you know, ask more questions if you want. But yes, it goes in every direction because our microbe composition is influenced by the environment.

And if you do things that help to change your stress levels and the types of inflammatory cells that your body is inhabiting. by, then that changes the environment and it changes which microbes are winning the battle of survival in your gut at that moment and which microbes are there to break down the foods that you're eating. So yeah, there's a very tight connection between our guts and our minds, but we're really at the beginning of figuring that out. There's a few conditions that we are starting to have really good evidence like for Parkinson's disease. There's symptoms in the gut arising well before other symptoms like constipation. And that was one of the clues that helped us try to disentangle how the microbiome is involved in Parkinson's disease development. I'm so curious

in 10 years, like what we're going to understand better. But there's really cool evidence emerging all the time. So you've mentioned several times that the microbes play important roles in digestion, etc. Do we know what like a good microbiome is? Like do we understand what your microbiome should be doing and what its composition should be. And is that true in the gut or in my nose or my ear? That is still a science question. And I think it's also maybe a philosophy question, even just to define health is really interesting. Our field has had a lot of interaction with philosophers through the years to try to define what health is. For example, at the operation nearby intestine for the product vaust, where they harvest so-called healthy fecal spores from

so-called healthy donors in order to treat the diarrheal pathogen C. diff, they have to decide who can be a healthy donor, and they screen people, and only 1% are considered eligible. To be clear, what we're donating here are BMs, right? Yes, so they get volunteers to come and poop on site four to six times per week, and then they harvest the spores out of their poop, and that is the product voused, which is being used to treat C. diff. It's one of two FDA-approved microbiome therapies in the country right now. It's got to be hard to schedule. Like, you can't just do that on Q. My son seems to be able to, but he's the only one I've ever met who can do that. Yeah. I think they have like a big line in the

morning, so people who can do that regularly. I remember asking in one of my classes once, like, who knows when they're going to poop every day? Like, is it like something you know when it's going to happen or is it like you're asking people about this in class and public got like raise their hand to talk about their poop schedule well it was when i had somebody from the company vouched visiting to speak and she had exactly the question you just had kelly anyway there were some people who were like how could you not know when you're going to poop i always know when and other people who were like i would never be able to guess that that's clearly like something that's different about each person but you know one percent of people are not the only healthy people and

I think that we need to think about what we mean by health differently. When I'm writing my ethics review approval documents for the studies that I do, I have a very expansive definition of what I think health is. And to me, health is someone who's out and about living their life. Like a student in my class is definitely considered healthy that otherwise they couldn't like show up and be a college student. If they have some allergy or some other kind of defined disease that's been diagnosed, in my mind that doesn't like knock them out of the category of being a healthy

person. And so that's a really difficult question to answer. But your question was, do we know what a healthy microbiome is? And that was actually what the goal of the human microbiome project was. It started in 2006, and they got 300 healthy donors in the United States to give samples. And healthy was defined somewhat more inclusively, I think, than the 1% that were accepted in that other donation context. And the goal was, like, what's the core human microbiome? Like, what are microbes that are shared between everyone. And the fascinating thing was that every time you added one more person to the study, the Venn diagram overlap got smaller and smaller until there was nothing left. So there were no core human microbes. Everybody is different enough that there just really isn't a core

human microbiome, depending how you define it. So you're saying, for example, person A is totally healthy in living their lives and having great poops and doesn't have anything in common gut bacteria-wise with person B who's also healthy and can eat beans and doesn't have terrible digestive problem. Yeah, people are extremely different from each other. If you only had two people, I bet you would find some overlap, but by the time you get to about 10 people, you probably don't have much overlap left anymore. And then really big differences occur when you look around the world. And so there's really cool patterns of people who live in less industrialized places where they eat more plants and less processed food. Their guts tend to be dominated by

plant breakdown microbes that are good at breaking down fiber and probably have other properties too. Whereas if you look in the industrialized world, and this is like so scary to me that most people in the industrialized world have a lot of mucus breakdown bugs in their gut. So basically we're starving our guts of fiber and as a result, the microbes are like turning to us and just like eating the mucus that's produced by the cells lining our gut. So there's this bug called acrimancia that's very common in the industrialized world. And bizarrely, it's even marketed as a probiotic because it has been associated with positive outcomes,

but it's breaking down the mucus, which is the only thing between you and sepsis. You have like literally millions of cells of microbes in your colon, and there's one layer of cells, this epithelial lining of cells, lining your gut, and if that barrier breaks down, the microbes get into your blood, and that's a blood infection.

That's called sepsis. deadly. And so your mucus lining that one layer of cells is a really important part of the barrier protecting you. And so weirdly, we have a lot of bugs that are breaking down that mucus. Maybe there's some kind of feedback there. I mean, these are all science questions. Maybe like the bugs breaking down the mucus stimulate its production and maybe that's like not all bad. But just the fact that it's so common in the industrialized world and missing in the parts of the world where people eat more plants, it kind of makes me want to have the plant type of microbiome, not the mucus breakdown one.

So then where can we expect similarities between microbiomes like you and I live in the same house? You mostly use similar foods, use the same toilets. Do we have similar microbiomes? Do we expect them to be similar? Definitely. That's one of the biggest signatures in every microbiome study after the individual is the household and the family. So when you collect samples from people who live together, they have so much in common. And so that's a really, really cool way to do a study. Like my favorite way to do a study is with household controls so you can compare people with the same background and otherwise to do longitudinal studies where you take samples from the same person through an intervention and then use their starting point samples as the

baseline because if you try to do it cross-sectionally where everyone is so different, it just doesn't work at all. And back to the household question, I mean, I really love studies that get into that. And I have a friend down in San Diego, David Pride, and he did a study once where he compared married couples who'd been living together for a long time with Craigslist roommates who moved in together. And after six weeks, they shared a quarter of the viruses in their gut communities. So sharing a kitchen and a bathroom is enough to share a lot. Huh. The Craigslist connection. Yeah. Yep. How much do our own individual microbiomes change over time? So if you looked at a family now or five years down the road, how consistent would their

microbiome be. They're quite consistent through time in families and households, but they're evolving because microbes have high mutation rates. They don't correct themselves as much as our cells do. So in a virus community, for example, there was one grad student who took samples from himself throughout grad school, which took a couple of years. And between the beginning and end of grad school, some of the viruses in their gut, I'm sure it was anonymous, so maybe I shouldn't say the name of But anyway, some of the viruses had mutated more than 3% in their genomes, which is the definition of a new virus. Each of our guts is kind of like its own little chemistat where evolution can keep happening. And so through time, enough mutations arise that it could even be considered

a new species of virus that's emerging. The other thing that happens is like, say you travel and get diarrhea and really shake things up or you take antibiotics, you can kind of like get your community steering to take a sharp turn after things like that. Wait, walk us through what's happening there. Like when you get diarrhea or when you get C. diff, what's going on there? Something is coming in and out competing the microbes in our guts or what's going on? Yeah, exactly. So oftentimes a diarrheal pathogen, what will happen is that they'll come in with some

toxin or some like really big hammer that causes big changes. Meaning that it kills the other microbes. Or that it just triggers an enormous. immune response, which brings in a lot of oxidative stress. And I was just telling you how the microbes in our colons hate oxygen. Well, inflammation is basically a pile of oxygen. So bringing in all those inflammatory cells and molecules, that's a tough condition for a lot of the bugs that live in our gut. And then you'll have an outgrowth of the kinds of bugs that can tolerate oxygen. In fact, when you study the microbiomes of people who have a terrible gut infection,

you don't often find that the bug causing the infection is the most numerous. This really surprised me, actually. I've done a few studies like this with cluster diodeficial infections here at the UCI Medical Center. And my naive expectation was that you would see like, oh, it's 90% C. diff, so they have a C. diff infection. But that's not what you see at all. You just see a bunch of bugs that can handle oxygen, basically. And then there's probably a small number of C-diff cells that are just dumping toxin that's causing all that inflammation. That's really mind-blowing.

I mean, especially if you start from the point of view of like diseases are microbes that come in, pathogens come in and colonize the humans. Now you're giving us a whole new way to think about what disease is. Now it's like microbial war where what's really being damaged are not the human cells, but like the microbes on our side that were doing their job for us. So it's really, we're sort of like a host. We're just like the battleground for this microbial confrontation. Yeah, exactly. I really like the concept of a holo-biome, which is the idea that, you know, you are your own genome and cells. And then you are host to a community of microbes, which comes from the environment that you live in.

So all the microbes in the environment that you live in, and then some subset of them colonizes you. And so part of your environment is your dust. diet and part of it is like how much time you spend playing with dirt. So like your exposure to microbes, who your roommates are, you know, stuff like that. Like sometimes people ask me, well, how can I get a healthy microbiome if I don't have one yet? And like one piece of advice would be to get a really healthy roommate who you knew how to help a microbiome. You're going to cause a lot of stress here. People are going to blame their diarrhea on their roommates now. If you only did the dishes, then I wouldn't have diarrhea.

Or maybe you cleaned the bathroom too much. I needed your good microbes, maddened them for that. So I've got a question about how we even quantify microbiomes. So bacteria, you know, they can undergo conjugation so they swap genetic material with each other. In just the course of a couple years, viruses are becoming new species because they're mutating so much. How do you define a species when things are changing so quickly and how do you compare between individuals when there's all this variability? Yeah. Yeah, what a great question.

And, like, I've been in this field long enough that I've watched the pendulum swing back and forth on how we make those definitions. Sometimes it's driven a little bit by technology. But, you know, basically there have been people thinking about microbial communities for more than a century. So, like, it goes back to there was a Ukrainian microbial ecologist who was studying pond scum in Switzerland, and he made these columns called Winogradski columns, which had, you know, just what I was talking about with the oxygen gradient,

where you'd have oxygen-loving bugs at the top, and then their waste products become the treasure of the next layer of microbes, which need less oxygen and have different strategies for metabolism. So those layers of microbes, you could even consider them to be the unit of selection that matters. And so it could be defined functionally almost. Since the mid-20th century, we started having molecular techniques for probing all of the microbes in a community. And this all started with environmental microbiologists. All the human clinical microbiology people were too busy isolating one

pathogen at a time and throwing anything that they didn't define as a pathogen down the drain as like unrelevant normal flora or something like that. So the environmental microbiologists got really good at these really cool molecular techniques starting with less resolution. So they had to define a species based on the information they could get. So we started like digesting common genes like ribosomal genes. and using restriction enzymes that we got out of hot springs and putting them on gels. And then like if the bands on the gel looked different, then that would be defined as a

different species. So probably we're talking like a few percent difference in genome because we were only looking at one gene. Even if that one gene is exactly the same, there could still be millions of years of evolution separating those two organisms. Then we got much better. Now we can sequence everything. And so when I first started in this field around 2008 or so, we defined a bacterial species as being 3% different from the next in this one ribosomal gene, and that was how we defined a species.

Since then, as our techniques have gotten better, we've leaned towards using even tighter definitions so we could look at organisms that are almost identical and only have one nucleotide difference, and then we would start to define that. as the taxonomic unit that mattered. Because these guys reproduce asexually, right? Yeah, they reproduce asexually, but they have pretty high mutation rates. They don't, like, correct all their mistakes. So, you know, for a virus, every progeny is a mutant, basically.

Like, I mean, think about that for flu or COVID. Like, I think there were actually really great visualizations about that since the pandemic that helped that become obvious to everybody, which is so interesting, right? If every time a virus makes a copy, it's a new mutant, some of those just fall flat, but that's not the strategy. The strategy is like most of them do okay. Some of them do amazing. Well, hey, look, I'm sure those virus parents love all their little mutants, right? All right. So let's take a break and think about the mutants in our life that we love.

And when we come back, we'll talk more about the microbiome. Hello, it's Honey German. And my podcast, Grazacus come again, is back. This season, we're going even deeper into the world of music and entertainment with raw and honest conversations with some of your favorite Latin artists and celebrities.

You didn't have to audition? No, I didn't audition. I haven't audition in, like, over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We've got some of the biggest actors, musicians, content creators, and culture shifters

sharing their real stories of, a failure and success. You were destined to be a start. We talk all about what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing vibras you've come to expect. And of course, we'll explore deeper topics dealing with identity, struggles,

and all the issues affecting our Latin community. You feel like you get a little whitewash because you have to do the code switching? I won't say whitewash because at the end of the day, you know, I'm me. Yeah? But the whole pretending and code, you know, It takes a toll on.

Listen to the new season of Grasas Has Come Again as part of My Cultura Podcast Network on the IHartRadio app, Apple Podcasts, or wherever you get your podcast. A foot washed up a shoe with some bones in it. They had no idea who it was. Most everything was burned up pretty good from the fire that not a whole lot was salvageable. These are the coldest of cold cases, but everything is about to change. Every case that is a cold case that has DNA right now and about. backlog will be identified in our lifetime.

A small lab in Texas is cracking the code on DNA. Using new scientific tools, they're finding clues in evidence so tiny you might just miss it. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, got you. On America's Crime Lab, we'll learn about victims and survivors. And you'll meet the team behind the scenes at Othrum, the Houston Lab that takes on the most hopeless cases. to finally solve the unsolvable.

Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Your entire identity has been fabricated. Your beloved brother goes missing without a trace. You discover the depths of your mother's illness the way it has echoed and reverberated throughout your life, impacting your very legacy.

Hi, I'm Danny Shapiro. And these are just a few. of the profound and powerful stories I'll be mining on our 12th season of Family Secrets. With over 37 million downloads, we continue to be moved and inspired by our guests and their courageously told stories. I can't wait to share 10 powerful new episodes with you, stories of tangled up identities, concealed truths, and the way in which family secrets almost always need to be told. I hope you'll join me and my extraordinary Extraordinary guests for this new season of Family Secrets.

Listen to Family Secrets Season 12 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I had this overwhelming sensation that I had to call it right then. And I just hit call. I said, you know, hey, I'm Jacob Schick. I'm the CEO of One Tribe Foundation. And I just wanted to call on and let her know there's a lot of people battling some of the very same things you're battling. And there is help out there. The Good Stuff podcast, season two, takes a deep look into One Tribe Foundation, a non-profit fighting suicide in the veteran community.

September is National Suicide Prevention Month, so join host Jacob and Ashley Schick as they bring you to the front lines of One Tribe's mission. I was married to a combat army veteran, and he actually took his own life to suicide. One Tribe saved my life twice. There's a lot of love that flows through this place, and it's sincere. Now it's a personal mission. Don't have to go to any more funerals, you know. I got blown up on a React mission. I ended up having amputation below the knee of my right leg and a traumatic brain injury because I landed on my head.

Welcome to Season 2 of The Good Stuff. Listen to the Good Stuff podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, so we're back and we're talking to Professor Katrina Whiteson of the Weissan Research Institute about the microbes in our body. how they influence our world and shape our lives. And we're talking about the links between microbiome and health. And in a minute, I want to ask you about what we can do to impact our microbiome. But you've sort of laid out this picture that, like, these things are in our guts. We don't really understand why they're so different from person to person.

We can't even really define health. We don't understand necessarily what microbiome you need to have healthy function. But we know that there's a connection between microbiome and health, right? And I've heard about people talk about connections between like the microbiome and like Alzheimer's or microbiome and autism and microbiome and all sorts of things in our lives. How much do we know about the impact of the microbiome on these conditions? Can I super fast interject? I love that Katrina is president of the Whiteson Institute,

but I do feel like we've never actually mentioned that Katrina is also a professor at UC Irvine and has her own lab. Have we given her actual credentials at some point? Oh, yeah, she does have a secondary affiliation at UC Irvine. okay all right so she is incredible in lots of ways but okay all right sorry go ahead with the question that's nice of you well i mean yes we have observational evidence associating microbiomes with health on a lot of different fronts and i mean just it's hard to even know where to start but one place i could start is that when i started my lab at e c irvine in

2014 right when microbiome was becoming big in the literature and everybody was excited about it I had 100 labs contact me wanting to collaborate in that first year. I think I had one grad student just beginning to join my lab. We obviously couldn't do 100 collaborations. So I ended up joining forces with an ecologist here, Jennifer Martini, and we started a microbiome center. And in the last 10 years, I have gotten to study easily 100 different types of microbiomes. Like, name a type of body sample you could think of.

I've probably got some in our lab freezer, and I've probably studied its microbiome. and that goes for like lots of different kinds of creatures, including sharks that eat seaweed from Donovan Germans lab, for example. So we have been going around and like watching what the microbiomes look like and taking notes and associating that with health. So a lot of the information we have is observational. So we still have in the future a need to do more interventional studies where we ask, how does the microbiome change when you manipulate it in a certain way? You know, now we kind of know that microbiomes are associated with obesity and cancer and so forth, but then what do we do about it? That's kind of like the next 10 years of challenge. And there's a few glimmers of really, really exciting outcomes that make me think it's going to be possible. So like,

for example, cancer treatment is an area that I think has a lot of room for big improvement where my colleagues at MD Anderson, Jen Wargo, for example, have done studies showing that when melanoma patients are getting immunotherapy, which usually only succeeds about 30% of the time, and the 30% of people who have a successful immunotherapy tend to have a certain kind of microbiome. Well, it turns out if you do a fecal transplant from someone whose immunotherapy succeeded into someone whose immunotherapy failed, you increase their chances of a good outcome. Or if you ask how much fiber people ate, people who ate more than 20 grams of fiber per day, have double the progress-free survival when they're doing immunotherapy.

And now they're even doing intervention studies where they're getting people on immunotherapy to eat fiber, and they're watching to see if that increases their healthy outcomes. And that's not published yet, but I'm very optimistic. So those are the kinds of things I could see happening in the future. We even know that vaccine efficacy depends on fiber intake. So like if you want to have a good response to a vaccine, eating well and having enough plant fiber to support your gut microbes and keep your immune system going will actually make you have a more robust response to a vaccine. See, I knew tacos are good for you. I always knew that.

Tacos. Exactly. What are you putting in your tacos? Why are your tacos high fiber? Oh, I see. Not all tacos have beans in them, Daniel. Real tacos? Are you having like weird Virginia tacos with no beans in them? I guess so. Yeah, I guess so. Even Texans put beans in their chili. I know, exactly. No, no, Texans. have no beans in their chili that's very important katrina okay well all right so you've mentioned a few ways that we can impact our microbiome let's dig into those in detail so you've talked a couple times about fecal transplants and people are probably wondering like what are you talking about here when i think about transplant i think about taking a kidney out of one person's body and putting it in somebody

else's body now i'm trying to think about what a fecal transplant means like walk us through this what's going on here how does this work at all what do we know about it okay well fecal transplants refer to taking a healthy microbiome from one person and trying to give it to another person. We have been doing this since ancient times. So more than a thousand years ago in China, people were using what they call golden soup to treat diarrhea. And actually, since I teach about this in my big classes, and I've heard so many good stories from my students who bring up, oh, yeah, my family's from the south.

And we used to do cow patty tea to treat diarrhea. What? Really? Yeah. Southern hospitality. There you go. Yeah, you guys have a lot to look forward to when you come to visit. I mean, this is something you would only do when you're in dire straits, right?

But if you've been having diarrhea and you weigh 65 pounds and you can't walk, you might be up for trying something bizarre to survive, you know? Absolutely. A modern time story comes from the Mayo Clinic in Minnesota where a woman who had a C. diff infection, Diff is typically caused by taking antibiotics and decimating your healthy microbiome, which makes it easy for C. diff, which forms spores in your gut to rear its head and make toxins and cause diarrhea. And it can get really recurrent and difficult to treat. And the standard of care, ironically, is more antibiotics, which caused the problem in the first place. So a woman

at the University of Minnesota at the Mayo Clinic, her doctor had this, you know, kind of crazy idea like let's take a fecal sample from her husband and transplanted into her and see if we can help this situation get better. And her symptoms improved within a day. She went from having had diarrhea every 15 minutes and she was in a wheelchair and was like unlikely to survive to the next day her diarrhea was resolved. It's incredible. I think you're skipping over some of the crucial steps involved. Like when you talk about this fecal transplant, are we talking about the northern route, the southern route? Like how do you get it from him into her? Yes, good question. You've heard me say my northern and southern route joke.

Well, I mean, your digestive tract is a tube, so you have a couple of entry points. She's so polite. It's amazing. And so to do a fecal transplant, you can take a healthy sample, put it in the blender, and then get it into a nasal gastric tube down into your stomach from the northern route. Or you can do it more like an enema. into the bottom part of your digestive tract. You can also make capsules, and you would need to swallow about 20 or 30 glycerin capsules

that have poop in them to have an impact, which reminds me of a favorite story. Stanley Falco at Stanford in the 1950s was a hospital technician as a young man. He's now, like, every now he was one of the fathers of the hygiene hypothesis, but as a young man, he was helping a surgeon who had this idea that they could hide healthy fecal samples

from before a patient had surgery in their ice cream and they could eat that post-operatively as they were waking up because a lot of people were getting diarrhea from the antibiotics they were getting in the surgical ward. And without telling them, they had them eat ice cream with these fecal glycerin caps in there.

And it was working great. Like nobody was getting diarrhea. But when the director of the hospital found out, he fired them. I mean, yeah, yeah. No more brownie chunk ice cream for you. But they all recovered, and that thinking got them really far. So that was actually very ahead of their time to be doing that in the 1950s.

But then it was around 2010 or so that this story in Minnesota I told you about emerged. And then since then, it's become like really a sought-after treatment for C-DIF, but very hard to regulate. It's kind of similar to blood donation. Like we haven't figured out how to make synthetic blood. And it's still a quest. And similarly for a fecal material, it's a quest. to figure out like what is even in there, which parts of it are needed to make a fecal transplant successful. So what's happening is that like my microbiome is devastated, which is why I have

diarrhea. I'm getting somebody else's community that comes in and then grows into some healthy community. That's the idea? Well, that might have been initial thoughts on what the idea was. But interestingly, in the last 15 years, we've tried dissecting the poop into its various components. And so fascinatingly, we've discovered that many of the different components are enough to work as a fecal transplant. So you can filter the poop and only give the liquid supernatant, which has molecules and maybe viruses, but certainly not bacterial cells. And that's enough to cause a successful so-called fecal transplant.

We call it a filtered fecal transplant, and that still works. Or you can just isolate the spores out. Those are cells, for sure, and give that as a treatment. That's the FDA-approved treatment for the product voused. or you can take a whole fecal community. There's a Swedish poop from the 1990s that has been cultivated anaerobically ever since then. A historic poop? Yes.

And my students are like, hey, that poop is older than me. Whenever I use the bathroom, I never imagine it's going to go down in history. But this one really did. Yeah, this one poop has saved like probably thousands of lives. This one poop has been cultivated anaerobically for many years. And so presumably none of the initial molecules from that poop are present, but just the progeny of all those generations of microbial growth. And that has been enough to cure C. diff in many, many different people.

So to be honest, it's still a science question, like what you actually need to make a fecal transplant work. There also have been famous failures. There were phase three clinical trials of cocktails of microbes that people put together in the pharmaceutical industry, that that would work and it didn't. So there's a jean-secois about the poop that just works perfect. So you mentioned that when you've got the liquid supernatin without any of the bacteria in it, but you've got their metabolic excretions plus viruses, it works fine. Yeah. Does that suggest it's the viruses that actually matter? What a cool question. I love that question. I don't know the answer, but it has been shown in like a number of different ways.

There was a group in Germany in Kiel that showed this with the viruses, with the filtered fecal filtrate. And then there's a group at the University of Copenhagen who have done really extensive studies in this really cool model of baby piglets. And their goal is to be able to help preterm infants in the NICU. And it's such a good idea because it would be very dangerous to give live microbes to preterm babies whose guts are in really bad shape. But if you could do it with the viruses, you might be able to create an environment

that helps the gut microbiome develop successfully. And, like, babies in the NICU have really bad outcomes with their guts. Like, a third becomes septic, a third get necrotizing enterocolitis, and a third have what they call healthy outcomes, but, I mean, they're really in dire straits. And so I love what the group at the University of Copenhagen is doing because they're starting in a model of baby piglets, which is pretty similar to a human model.

And I am optimistic that it won't take too long before they'll feel like it's safe to try it in babies, because the room for improvement there is just enormous. So that, to me, is like a really, really cool way that we could improve health. So if you get a transplant from somebody else, they have a different microbiome. It's no guarantee that it's definitely going to work for you. Is the ideal transplant a donation from yourself? Like, if you're out there having good poops every day,

should people put some of that in the freezer for the day when they have surgery or diarrhea? I really like that idea. It's certainly been a topic of conversation in our household. Don't dig around in our freezer unless you want some surprises, by the way. Well, not your favorite part of our freezer, I know, but I appreciate your open-mindedness. And by the way, when my students have to put fecal samples in the freezer for our studies, we joke about the right way to do that. And like if your roommates don't like the idea, just empty out a box of strawberry popsicles

or like chicken nuggets and you can just hide your samples in there. And if they're trying to steal a popsicle, I mean, that's on them. Oh, they're going to get a popsicle. It's just not going to be strawberry. Exactly. After this conversation, I'm never going to look at popsicles again. Same way again. Poopsicles, yeah.

So the question was, could we do, like, auto, like, self-fecal transplants and have that work? And that has been studied in a lot of different contexts, also for, like, recovery from antibiotics. If you really know that you're healthy, like, maybe everybody should be banking their own sample at some point in their life when they just were digesting, really. well and they were 18 and had like been eating really well for the summer or something, save a moment of that glorious part of your health in the freezer so you could restore yourself to it. I like that idea. I've proposed this for different kinds of context. Like one time I wrote a proposal about helping people who are going to have to have radiotherapy for cancer. And often people get essentially diarrhea and other really rough consequences of the radiation

treatment. So the idea was to restore their health to what they were. before the treatment, but somebody who has cancer might have cancer promoting properties in their own fecal microbiome. So you could inadvertently bring them back to getting cancer again. I mean, this has been studied extensively, like this kind of approach has been used. There was a big study in New York City of people who were getting bone marrow transplants for blood cancers, where they did transplants from people's before fecal sample in order to try to help them avoid getting, I mean, people get terrible infections after getting cancer treatment. So this is an area, again, kind of like the preterm babies. There's like a ton of room for improvement there. But the

concern is that you would cause cancer again. So maybe a healthy donor is safer. And then I hear your question, well, what if the healthy donor is really different than you? Well, another thing that happens is it's rare that we follow up our studies long enough to really see what happens. But there was one study of autistic children where they did fecal transplants from a stranger, like a a healthy donor, not a family member. But then they followed up for two years, both the kids with autism and a healthy sibling in the same household. And I loved that they did this for two years. This is Rosie Crosmul Lake Brown, Arizona. And they found that at first, the autistic children who received the fecal transplant from a stranger donor, their guts were more similar to the

healthy donor. But after two years, their gut microbiomes resembled their siblings. siblings more, but they did have higher diversity. So it's almost like the fecal transplant kick started the capacity to carry a higher microbial diversity. But then all those strains got replaced by strains that were available in the household. So the household influence is really important. And it makes me wonder, like, when people get married, there's going to be a battle of the microbiota's and somebody's going to win. And that hasn't really been studied that much, you know. Till diarrhea do us part.

Can we talk about the probiotic industry? You mentioned earlier, it's $80 billion. And I feel like I see pills and powders and yogurts promoting probiotic this and probiotic that. What's in those and what's your take on whether they're likely to do anything? Well, that's a really big question. It is a really big industry. I was even just comparing the size of the probiotic industry and the antibiotic industry.

And I think the probiotic industry might. even be a bigger money maker than antibiotics, but it's close. But I mean, that's amazing to me. $80 billion, like, that's close to the GDP of many nations. And so whether it could work is one question. And yes, the idea of a probiotic makes sense. I mean, if you could get the right bug to the right place at the right time, that's a great idea. It could definitely work. When we say probiotic, that includes fermented foods like yogurt and kombucha and kiefer and miso. And those we actually can see really kickstart diversity in our guts, not necessarily because the bacteria in those products are colonizing our gut,

but they can kickstart diversity in a good way. Most people, when they take a probiotic and many packages claim that it's going to directly increase your microbiome diversity. I think a lot of people, when they eat a probiotic, imagine that now that bug is happily living in their gut, and they just, like, got their community a little happier. Now, most probiotics actually don't do that. Most are transient.

So if you are taking those pills and then you measure people for a week, you'll see a washout period and after a week or so it'll be gone, which is probably not what people imagine. You also might not want the probiotic to stick. So I always remember the story of a startup in San Francisco where they evolved probiotics that were good at binding to mucus with the idea that they could persist in the gut. But they forgot about gum mucus and everybody got cavities in their lives. a study.

I'm not laughing. Biology is so complicated. I know. So on average, probiotic packages, they don't have to have evidence for the claims they make on the packages. So they can say some pretty fantastical things.

And actually in my microbiomes class this quarter, we had a probiotic Suss score, like a suspicion score activity where everybody had to go find a probiotic with crazy claims on the package. and then try to investigate the claims and, like, what evidence there was for them. And there was not usually a whole lot of evidence.

And the students had amazing comments afterwards that were like, man, if I saw a celebrity claiming that a probiotic worked, I just would believe it. It never occurred to me to, like, investigate the evidence. And I'm like, you guys are science students. I'm glad if you're learning that. Yeah, it's important. Yeah. So, you know, just off the top of my head, you know, there's probiotics out there that are named

like, happy hoo-ha. and they claim to improve your vaginal microbiome or like, you know, anyway, there's some pretty funny ones. But there are some probiotics that are well investigated and people are doing studies with them. And sometimes they're not sharing the evidence in order to protect their IP. So it's complicated. But the way the industry is regulated is just that the probiotics have to be generally regarded as safe or grass, which is not a very high standard.

I mean, it's a high standard in the sense that, like, this thing's not going to kill you. That's good. Might give you cavities. Might give you cavities or might just do absolutely nothing. And, I mean, the supplement industry, even beyond probiotics, is an enormous industry, and there's very few claims. And it's pretty hard to know, I mean, even for, you know, ourselves, like Daniel and I, we have a son who's an athlete, and he's always, you know, really willing to do what it takes to be healthy. And so we've had a lot of conversations about what we understand about what's in a supplement versus is what we understand about what's in a food.

And, you know, with the tools we have in our own households, we can't really assess the safety of food or supplements. That's why we need infrastructure and institutions that help us understand that. But a lot of the things that we can buy in packages might have stuff that's dangerous in them, and we have to be really careful. So my general instinct is to lean towards food. And, you know, the advice to generally not eat things that you're going to, grandparents wouldn't recognize as food or maybe it has to be our great grandparents now

because a lot of the processed foods that are available to us these days with tons of ingredients we can't even pronounce it could be really damaging our health. It's not like I have really great evidence for every single one but I think that leaning towards eating things that you can recognize tends to work the best for the evidence that we have right now. And earlier on you mentioned fiber and beans. Why is fiber something good? eat. I mean, if you're not going to do a poop transplant and you're not buying happy hoo-ha or whatever, if you're just going to try to do this through like healthy eating and food, tell us why fiber is important. Definitely. So fiber is the part of carbohydrates that doesn't get

digested very quickly. It's longer chains of carbohydrates that your human enzymes can't even access. So the way to figure this out is if you look at an nutrition label, it'll list the total carbs and then it'll list the subset of the carbs that are fiber. So for a piece of white bread, it might be like 19 grams of carbs, one gram of fiber. Wheat bread might be 19 grams of carbs, five grams of fiber. Okay, cool. So now we're talking like, you know, nearly a quarter of the carbs in that piece of bread is fiber. It's going to be slower to hit your blood sugar levels. It's going to persist in your digestive tract down to your colon where all the microbes live and give them some food. So that's pretty good. Now let's talk about beans and lentils. Half of the carbs in beans and lentils are in the form of

fiber. So if you eat a cup of black beans or old navy beans or lentils in a day, you'll get probably 10 or 20 grams of fiber out of the 30 or 40 grams of carbs. That's half of your fiber needs for the day. So the daily recommended allowance of fiber in the U.S. is 25 to 35 grams per day. And we're usually getting half of that. Most Americans are getting 10 to 15 grams per day. So we all need to think about how to fill our fiber gap. You always hear about how we're not eating enough protein. I mean, to be honest, we're probably eating plenty of protein in the United States, but we really are not eating a fiber. If you eat fiber, you are fueling the microbes in your colon. And then if you do experience some kind of stress, whether it's antibiotics or diarrhea or just like literally stress that

causes inflammation and oxygen descending upon you and making it harder for those bugs to thrive in your colon, when you have fiber in there, you've given the bugs a place to hide out. So you can weather the storms of any kind of other fluctuations in your life better and keep the microbes happier. So like if you did know you had to take antibiotics, I would definitely really recommend making sure you're eating enough fiber and fermented foods actually are another really good contributor. All right. So that's scientific evidence that chili should have beans in it. You settled that age old question. I mean, I don't think there's anyone who would disagree that if you wanted to protect your microbiome, having beans and your chili would be a good idea.

All right, everybody. So tonight, grab your beans and your be no, and hopefully Katrina Weitzin will be back on the show in not too long. Thanks for spending some time with us today. Awesome. Thank you. Daniel and Kelly's Extraordinary Universe is produced by IHeart Radio. We would love to hear from you. We really would. We want to know what quite a lot. you have about this extraordinary universe. We want to know your thoughts on recent shows, suggestions for future shows. If you contact us, we will get back to you.

We really mean it. We answer every message. Email us at questions at danielandkelly.org. Or you can find us on social media. We have accounts on X, Instagram, Blue Sky, and on all of those platforms, you can find us at D and K Universe. Don't be shy. Write to us.

Every case that is a cold case that has DNA right now in a backlog will be identified in our lifetime. On the new podcast, America's Crime Lab, every case has a story to tell, and the DNA holds the truth. He never thought he was going to get caught, and I just looked at my computer screen. I was just like, ah, gotcha. This technology's already solving so many cases. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy,

which is more effortful to use, unless you think there's a good outcome. Avoidance is easier, ignoring is easier, denial is easier, complex problem solving, takes effort. Listen to the psychology podcast on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Let's start with a quick puzzle. The answer is Ken Jennings' appearance on The Puzzler with A.J. Jacobs. The question is, what is the most entertaining listening experience in podcast land? Jeopardy-truthers believe in... I guess they would be Kenspiracy theorists.

That's right. They give you the answers and you still blew it. The Puzzler. Listen on the I-Heart radio app, Apple Podcasts, or wherever you get. Your podcasts. Hi, it's Honey German, and I'm back with season two of my podcast. Grazias, come again. We got you when it comes to the latest in music and entertainment with interviews with some of your favorite Latin artists and celebrities.

You didn't have to audition? No, I didn't audition. I haven't auditioned in, like, over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We'll talk about all that's viral and trending, with a little bit of cheesement and a whole lot of laughs.

And, of course, the great bibras you've come to expect. Listen to the new season of Dresses Come Again on the IHeartRadio app, Apple Podcasts, or wherever you get your podcast. This is an IHeart podcast.