Bonus Episode: Nutritional Microbiology (GUT HEALTH & DIET) with Miguel Freitas and Elaine Hsiao

Speaker 1 This episode is sponsored by Activia. I know we love fun facts, and I know we love guts here.
Your digestive tract and mine too, made up of over 200 million neurons.

Speaker 1 People call your guts your second brain. There's so much going on down there.
You're out there, you're having a lazy day, maybe. Meanwhile, your guts are Grand Central Station.

Speaker 1 And what can you do for that city? Well, Activia is the number one probiotic yogurt brand. They're backed by 20 years of gut health research.

Speaker 1 You know me, I love gut health research, and they have explored this through over 15 clinical studies.

Speaker 1 Activia is not just a a yogurt, it is decades of science and curiosity all packed into something that you can eat. So if your brain is interested in your guts and vice versa, activia might be for you.

Speaker 1 Let's feed our brains and our guts. Your gut is where it all begins.
So enjoy activia as part of your daily gut health routine.

Speaker 1 Enjoying activia twice a day for two weeks as part of a balanced diet and healthy lifestyle may help reduce the frequency of minor digestive discomfort, which includes gas, bloating, rumbling, and abdominal discomfort, which you probably don't like, but you probably do like yogurt.

Speaker 1 Oh, hey, it's the lady on the bus wearing mismatched socks, Allie Ward. This is a special bonus episode of Ologies, wherein we travel deep, deep into the busy world of your guts.

Speaker 1 So in 2018, you may remember we had a legendary conversation with Dr.

Speaker 1 Elaine Shao, a microbiome researcher at UCLA, and learned all about the hot cauldron of your guts and who lives there and what they're doing for you. around the clock.

Speaker 1 And in this 2025 update bonus, we chat again with Dr. Shao to get some updates on the the last seven years of her research.
It's a lot, a lot of good stuff.

Speaker 1 I was also curious about cultured foods, and I was invited by Danone to see their brand new research facility in France. But it was two days before your pod mother Jarrett's 40th birthday.

Speaker 1 And alas, I could not teleport. But I did the next best thing.

Speaker 1 And while I was on the East Coast this month, I got to hang out with a lead nutritional microbiologist and a director of the nonprofit Danone Institute, North America, and ask a million questions about good versus bad microbiota, how they simulate a human gut in a lab, what exactly is a prebiotic versus a probiotic, and why are they such good friends?

Speaker 1 How diet can impact not only your gut health, but also your heart and your brain, and if friendly yogurt critters are robust enough to make the journey from your mouth to your toilet.

Speaker 1 So thank you, Danone and Activia, for having me and for acting as a sponsor of this episode, which this week let us donate to the LA Regional Food Bank as well as to give directly.org allergies as a part of this month's Pods Fight Poverty initiative.

Speaker 1 So, thank you, sponsors, and do check those links out in the show notes. Okay, back to it.

Speaker 1 Hang out, bring your ears, and your mouth, and your intestines to chat with not one, but two gut microbiome microbiologists for this bonus episode with a neuro microbiologist and a nutritional microbiologist, Dr.

Speaker 1 Elaine Shao and Dr. Miguel Freitas.

Speaker 1 And I'm going to have you hold this and you just kind of hold it like if you were doing karaoke.

Speaker 3 It's like this.

Speaker 4 Yeah, I don't do it very often, but I like it. Megalphretis.

Speaker 1 In terms of an ology, let's just say, would you consider yourself a gut microbe, a gut microbe microbiologist? Or what would you say that your urology might be?

Speaker 4 I would say that I am cell biologist or

Speaker 4 cell microbiologist.

Speaker 1 And were you always interested in the little things? Did you have a microscope? When did you start going from like big to tiny?

Speaker 4 I did have a microscope.

Speaker 3 You did?

Speaker 1 How old are you?

Speaker 4 I was young, probably

Speaker 4 seven, eight. Yeah, I did have a microscope.
I grew up in a family of medical professionals.

Speaker 4 My dad was a radiologist. My mom was a nurse.

Speaker 4 They both met at the hospital. So I pretty much grew up in a hospital setting.
That's where I would go after school.

Speaker 4 I got the passion of little things and microbiology. I can still see the microscope.
It was white. It was quite cool, actually.
It was, you know, one of those that you can change the lenses.

Speaker 4 Funny that you mentioned that because I did have one and I know what it is in my dad's house. And it was a big important first step for me to get into science for sure.

Speaker 1 I think it's so interesting how much mystery and what's working right in front of our eyes that's keeping us alive. And when we talk about microbes a lot, I feel like a lot of people think

Speaker 1 viruses or bacteria or bad germs. If it's small and you can't see it, it's probably bad.
But as you know, we couldn't live without all the the critters inside of us.

Speaker 4 True, yeah.

Speaker 1 And according to a 2016 study, revised estimates for the number of human and bacteria cells in the body, microbial cells in the body, once they were thought to be 10 times more prevalent than our own human cells, it's actually closer to a one-to-one ratio.

Speaker 1 And this study states that thoroughly revised estimates show that the typical adult human body consists of about 30 trillion human cells and about 38 trillion bacteria.

Speaker 1 So it's actually of the same order as the number of human cells. And their total mass in your gut is about 0.2 kilograms.
So about half a pound of you is other tiny little people.

Speaker 1 But they outnumber you by 8 trillion. However, shocking maybe no one, much of the initial research focused on some standard person known as, quote, reference man.

Speaker 1 who was a male between the ages of 20 and 30. But hi, did you know that people assigned female at birth have a microbiome? Also, they do.
It's true. They're humans.

Speaker 1 They also have more in their nethers.

Speaker 1 And in the 2019 study, Sex Differences in Gut Microbiota, oddly, this was in the Journal of Men's Health, and it clarifies that some of the more recent research notes that there are over a thousand different bacterial species in the human colon, and each individual harbors at least 160 different species.

Speaker 1 And the ratio of the numbers of bacterial cells to human cells was different between males and females, with the vagina people having about double the microbiome. What? So we're never alone.

Speaker 4 We have trillions of bacteria in our gut. So imagine how small they must be.
In a little cup of a yogurt, we can put billions

Speaker 4 of bacteria. So it's amazing.

Speaker 1 And we couldn't digest food without all of this help, without all of our roommates. We're roommates.

Speaker 3 We're roommates.

Speaker 1 And I feel like we're hearing more and more about it every year, where I don't think when I was growing up, we heard about the microbiome very much, you know.

Speaker 4 Same for me. I wasn't hearing a lot about the microbiome when I was growing up.
And even in school and college, it was quite a new thing to learn.

Speaker 4 We didn't have the sequencing techniques that we have today that show up 10, 15 years ago to understand

Speaker 4 what types of bacteria we have inside of us, how many bacteria we have inside of us. Now we're starting to understand a little bit better all the functions that the microbiome have.

Speaker 4 You're far from understanding the whole thing.

Speaker 1 What do those microbes do from

Speaker 1 your head to the other end of your body? Like what kinds of things does a healthy or unhealthy microbiome contribute to?

Speaker 4 It's an interesting question because the conversation on what a healthy microbiome is or not, it's also still not very well defined.

Speaker 4 There's a lot of associations between individuals that are, for example, obese in comparison to individuals that are lean, they have a completely different microbiome. Wow.

Speaker 4 People that have type 2 diabetes, they have a completely different type of microbiome. People that have anxiety, depression, kids with autism also have different microbiomes.

Speaker 4 But we're struggling to understand what causes what. So we do know that the microbiome is involved by association

Speaker 4 with many functions around our body, from brain to skin to cardiovascular disease.

Speaker 1 Do you want me to read off some studies as quickly as I can? I do.

Speaker 1 Okay, there's a Journal of MBC Microbiology 2022 paper: yogurt consumption is associated with changes in the composition of the human gut microbiome and metabolome, which found that yogurt consumption is associated with reduced visceral fat mass and changes in the gut microbiome.

Speaker 1 And the 2024 study, prebiotic fiber mixtures counteract the manifestation of gut microbial dysbiosis induced by the chemotherapeutic 5-fluorosil in a validated in vitro model of the colon, which showed that prebiotic fiber helped the good microbes flourish and then the bad ones decrease, which is important.

Speaker 1 As a 2017 study in the journal Advances in Nutrition, Yogurt and Cardiometabolic Diseases, a critical review of potential mechanisms, found that disruption to gut microbial balance, also known as dysbiosis, can promote inflammation, unhealthy body composition, and type 2 diabetes, plus increased fat storage, in case that's not what you want.

Speaker 1 I also stumbled upon an eyebrow raising kind of a head scratcher of a 2025 study in the very lauded Frontiers in Nutrition Journal.

Speaker 1 It was titled, Dietary and Environmental Modulation for the Gut Environment. Yogurt promotes microbial diversity, while chloride hot springs improve defecation status in healthy adults.
What?

Speaker 1 Apparently, someone really wanted to learn if yogurt and hot springs, when used in well-monitored conjunction, could show, quote, numerical improvement in defecation scores, which it did.

Speaker 1 There are literally thousands of yogurt and nutrition studies, but this one is just, it's close to my heart, it's close to my intestines. What a banger.

Speaker 1 If one day you would love to get to better know your microbiome, but you're not really keen on pooping in a tray and handing it over to a lab tech, I understand.

Speaker 1 You may want to read this 2025 pilot study titled Yogurt Reintroduction and the Circulating Microbiome in Healthy Volunteers, Protocol for a Prospective Longitudinal Species-Controlled Crossover Clinical Trial, which looked at whether scientists can figure out what's up with your microbiome just by looking at your blood samples.

Speaker 1 For me, I would opt for the needle over the tray, personally.

Speaker 4 So there's so many studies showing those associations.

Speaker 4 Now we need to understand how can we inverse, how can we change either through food or through medication, how can we change the microbiome to see if we can also change the health status of somebody.

Speaker 4 You know, fibers actually increase the diversity of the microbiome. Certain fermented products increase the diversity of microbiome.

Speaker 4 We also know that individuals that have typically a higher diversity of microbiome tend to be associated with at least less disease status. So

Speaker 4 the functions are so many.

Speaker 1 And you may remember very well our 2018 microbiology episode with the wonderful and amazing Dr. Elaine Chao, a researcher and an associate.

Speaker 1 professor at UCLA's Department of Integrated Biology and Physiology.

Speaker 1 And her work examines, I love this, the interactions between the the microbiome and the brain and behavior, as well as the immune system, and even the link between the microbiome and epilepsy.

Speaker 1 I just adore her. I'm fascinated by her work.
She's so great. So I caught up with her this past week to just lavish her with praise and ask what's new.

Speaker 1 The number of papers that have come out since I talked to you last is staggering. Your lab is doing so much work, everything from

Speaker 1 serotonin in the gut to extra intestinal symptoms and irritable bowel syndrome associated with stress reactivity in the gut market. I was like, this is everything.

Speaker 1 And I wanted to ask a little bit about where your lab's research has gone since we talked last and what have been like some really interesting studies that you've gotten to work on that you feel like have just changed the game.

Speaker 2 Yeah, things. I can't believe how much time has flown.
Things have really, really changed a lot since then.

Speaker 2 Some of the main things is that, you know, at that time, people were just establishing microbiome links to brain and behavior. And now it's not a question of whether it happens.

Speaker 2 It's more a question of how.

Speaker 2 And so all these, I guess, past seven years have been really focused on figuring out mechanisms for signaling between the gut and the brain and the microbes that are there.

Speaker 2 We've been really focused on what molecules do microbes make and which ones can actually signal directly to vagal neurons that touch the gut and extend directly in the brainstem.

Speaker 1 And how about Miguel's lab work? When it comes to your research, what does that look like for you?

Speaker 1 What types of things are you looking at or sampling or what kind of data do you have to get or what kinds of scientific research do you have to sift through?

Speaker 4 So interesting you asked that because a few weeks ago we just opened a new laboratory at our research center outside of Paris called the One Biome.

Speaker 4 And it's a laboratory that is focused on understanding the population's microbiome.

Speaker 4 So when we talk about diversity of the microbiome, we're thinking about all the different genus that exist in our microbiome.

Speaker 4 And there's many genus and then there's hundreds of species and thousands of subspecies. And then as I said, trillions of strains.
Okay.

Speaker 4 And based on analysis of what's in that microbiome and and based on other general science, we know that this person, for example, is lacking Bifidobacterium, which apparently is one of the key species genus to have in the gut.

Speaker 4 So how can we develop a product, for example, that would promote the growth? of certain Bifidobacterium.

Speaker 1 And I know lactobacillus, lactobacillicus? Lactobacillus, yes.

Speaker 1 I see the word lacto and I think milk. So is there a reason why it got that name or why it's associated with probiotics?

Speaker 4 It produces lactic acid typically.

Speaker 1 Oh, there you go.

Speaker 4 So, you can have lactobacillus bulgaricus, you can have lactobacillus casei,

Speaker 4 you can have lactobacillus lactococcus, you can have many types of lactobacillus, but typically they all produce a certain amount of lactic acid. And that's really important to transform,

Speaker 4 in this case, a matrix that contains lactose, which is milk, into lactic acid, acid, and then gives the texture, the taste of fermented dairy products that you're familiar with.

Speaker 4 That doesn't mean that these bacteria actually are probiotics. We didn't talk about probiotics, but there's quite a big difference between a lactic acid bacteria and a probiotic bacteria.

Speaker 1 Oh, what's the difference?

Speaker 4 There's a lot of experts that looked into this. So it's a term that is

Speaker 4 used only for bacteria that have been studied, typically in clinical trials, to provide a health benefit. So, not all lactococcus or lactobacillus provide a health benefit.

Speaker 4 Some of these cultures are used to transform, to ferment bread, to ferment the milk, to make kombucha, for example, but that doesn't mean that they provide a health benefit, for example, in terms of supporting gut health.

Speaker 4 It needs to be studied. It needs to go into an RCT, a randomized controlled clinical trial with a placebo to show that it's actually doing something in your body.

Speaker 4 This is actually helping support your gut health by, for example, reducing the frequency of digestive issues. Or this is actually helping support your immune system.

Speaker 1 So to call something probiotic, it has to have quantifiable. proven benefits.
And yes, you've probably seen strains of lactobacillus or bifidobacteria.

Speaker 2 And those are the ones that you read off of over-the-counter probiotics or yogurts. And so time has told that they're safe in those strains and that they're culturable and easy to be studied.

Speaker 2 But I think a lot of the field is also really excited about

Speaker 2 next generation probiotics that are just really identified from our guts and like newly characterized bugs.

Speaker 2 But yeah, lactobacillus and bifidobacterium specifically is really prominent in like infant gut microbiome and is thought to have really beneficial effects for infants.

Speaker 1 And again, Dr.

Speaker 1 Shao and I had this really wonderful conversation years back about the research just emerging then, which was why it was just such a treat to catch up with her and talk about the world of laboratory stool samples.

Speaker 1 And while the conversations make me happy with her, it might also be the subject matter itself that is giving my brain just a little boost.

Speaker 1 I've read that like 90% of our serotonin is produced in in the gut. Some huge proportion.

Speaker 1 And do you, people who study this think that there is a correlation between kind of modern mental health and what our diet has become?

Speaker 1 How much of an effect on mental health are we able to discern from that?

Speaker 4 That's one of my passions. If I had to go back and do a postdoc or two postdocs would be on gut, brain, the gut, brain access.
It's very new also.

Speaker 4 And it's part of all those associations that we've been finding that there's a connection between our gut and our brain. And you're right.
A lot of the serotonin is produced in our gut.

Speaker 4 And maybe something that you also don't know is that after our brain, the gut contains the second most complex nervous system in our body.

Speaker 1 So when people say trust your gut, they're like,

Speaker 4 just one example. Trust your gut, but I have another one, butterflies in your stomach.

Speaker 3 Where does that come from?

Speaker 4 I'm sure you felt like, oh, yes. Oh my God, I'm feeling butterflies in my stomach, right? Which means what butterflies do in your stomach? They would like...

Speaker 4 put their wings like this and it tingles and you know you're feeling some sensation there and when does that happen usually that happens when either you're a little bit anxious or a little bit nervous for the right or the wrong reasons i don't know you're in love and you're about to go on a date and oh my god i'm so stressed i'm feeling these butterflies in my stomach that's your brain talking to your gut

Speaker 4 this is the connection between the brain and the gut but it also goes the other way when you don't feel good here

Speaker 4 if you have IBS if you have constipation or if you have distress in your stomach typically you're gonna feel it in your mind you're gonna be upset you're gonna be anxious and that's your gut talking to your brain so it goes both ways absolutely that's why our gut is called the second brain.

Speaker 1 Let's delve into that via a 2023 study in the Journal of Biomedical Science.

Speaker 1 It's titled Butterflies in the Gut: The Interplay Between Intestinal Microbiota and Stress, which notes this evidence that the gut and its inhabiting microbiomes may regulate stress and stress-associated behavioral abnormalities, and that the microbiota can regulate a stress response via intestinal glucocorticoids, don't worry about those, or the autonomic nervous system.

Speaker 1 So in terms of the sympathetic nervous system, that's the one that kicks in when you get a flood of adrenaline or excitement or dread. You can thank a reduction of blood flow to the stomach for that.

Speaker 1 That makes those butterflies. However, this study continues that gut microbiotic can actively modify your stress response via changing steroid synthesis and metabolism.

Speaker 1 So that can affect your stress signaling and your brain circuits, and it can ultimately impact complex behavior.

Speaker 1 So if you're an anxious mess, or maybe you're jittery with hope, hopefully, you can blame those trillions of living things colonizing your innards, putting the butt in butterflies.

Speaker 1 Also, who coined that? Who said that? Was it a peptic lapidopterologist? No, it was a lady named Florence.

Speaker 1 Florence Converse, a poet, a scholar, a writer to the Atlantic Monthly, a college professor, and historic for her time in the early 1900s, a well-known lesbian with a long-term partner.

Speaker 1 And Florence Converse wrote this 1908 children's book. She wrote, Timothy felt very dull.

Speaker 1 The three o'clock train going down the valley and the five o'clock train going up gave him a sad feeling, as if he had a butterfly in his stomach. So thank Florence Converse of Massachusetts for that.

Speaker 1 Also, who has the last name Converse?

Speaker 1 As it turns out, a guy named Marquise Mills Converse, also of Massachusetts, and the founder of a rubber shoe company, Converse. Her last name was Converse.

Speaker 1 I would like you to know, I was sucked into like a research vortex that was stronger than my free will.

Speaker 1 I spent a Friday night going down genealogy trees, up and down the limbs, to find out that yes, Marquis Mills Converse is the half-second cousin twice removed to Florence, and they are buried a scant 30 miles from each other outside Boston.

Speaker 1 Florence is buried side by side to her long-term spouse, who was also a literature professor, Vita Julia Dutton-Scudder. Anyway, this is a long aside, but I got excited.

Speaker 1 In history, it's enough to give you the butterflies, good and bad. And again, back to Elaine.
Her research focuses on that gut-brain connection from nerve signals to neurochemicals.

Speaker 1 Also, we have a whole episode, Molecular Neurobiology, with Dr. Crystal Dilworth, aka Dr.

Speaker 1 Brain on CBS's Mission Unstoppable, about what your neurochemicals are up to in your skull and, yes, other locations.

Speaker 2 A lot of serotonin, it's like about 90% of the body's serotonin is made in the gut.

Speaker 2 And then, in these past seven years, we've also found that what happens after the gut microbiome stimulates that serotonin is that that serotonin can then signal to local neurons that are really important for things like visceral pain and anxiety.

Speaker 2 And

Speaker 2 yeah, that's a really nice kind of gut-to-brain connection through peripheral neurons.

Speaker 1 I always feel like anxiety and

Speaker 1 IBS and

Speaker 1 the gut microbiome that I hear those discussed kind of in tandem. Do doctors know if that's just kind of the fight-or-flight response?

Speaker 1 Or do those kinds of stresses keep giving like kind of a gut punch to us?

Speaker 2 Yeah, absolutely. I think there's a really high comorbidity between IBS and anxiety and stress and anxiety.
And IBS is also now categorized as a disorder of gut-brain interaction. Really?

Speaker 2 And so it's really, yeah, so it's really clear that there's a gut-brain link in IBS and other GI disorders too. Wow.
Yeah.

Speaker 2 And I think it goes both directions where you can have stressors and the anxiety itself that goes, you know, from brain to gut to change the microbiome, but it could also go from the gut-brain direction.

Speaker 2 And so that makes it really complicated, but also interesting to tease apart.

Speaker 1 For more on this, you can see, for example, a recent 2025 paper out of her lab titled, Extraintestinal Symptoms and Irritable Bowel Syndrome are associated with stress reactivity in the gut microbiome in a sex-dependent manner, which found that with IBS, half of the people with it have extra intestinal symptoms.

Speaker 1 So pain or inflammation elsewhere in the body, and that many IBS patients also have somatic conditions, but that fibromyalgia and chronic fatigue syndrome, chronic pelvic pain, and joint disorder, they are more common in females.

Speaker 1 Fibromyalgia pain may have a gut solution though, and the journal Neuron noted that transferring fecal microbiota from fibromyalgia patients to rodent models confers pain hypersensitivity and depression-like behavior, which is then reversed by a fecal microbiota transplant to rodents from healthy donors, and that fibromyalgia patients experience significant symptom relief after fecal microbiota transplantation.

Speaker 1 So what about though for everyday gut issues that no one wants to talk about? So I talked about it with a guy I had met 20 minutes prior.

Speaker 1 And I know that everyone's like looking to have an easier time in the bathroom and also feel healthier.

Speaker 1 And I've always wondered when it comes to probiotics, which ones can survive our digestive systems?

Speaker 1 like how do we make sure it goes from our mouth to our gut how is it determined which ones survive and thrive and which ones are our DOA

Speaker 4 so a first important thing to know is not all probiotics are the same okay there's thousands of potential probiotic strains out there even the known has a collection with thousands of bacteria some of them that have been studied some have not been studied they can all have a potential to have a benefit in your body but you're right.

Speaker 4 In order for them to have a potential benefit in your body, and especially if the benefit is in the gut, they need to survive, right?

Speaker 4 So there are several tests and experiments that this tiny little bacteria can go through before they even consider the probiotic for a clinical study. And survivability is very important.

Speaker 4 We can test it in a model, for example, that mimics our digestive tract with the acidity of the stomach, with the esophagus, with the mouth, with the chewing, all of it.

Speaker 4 We can mimic all of that in a model and see if that particular strain survives the gut.

Speaker 4 And then that's when you start considering if it's a potential probiotic or not. And then you do other experiments, you put it in a clinical trial, and then...
it gets into a product ultimately.

Speaker 4 But it's a long process. But survivability is important.
And I think people don't know that our stomach is is it has a very low pH it's around one to three pH so to give you just an idea

Speaker 4 if you could put your finger in your inside your stomach you would burn your finger yikes i always tell this so this is this is why it's so important this survivability aspect and that's why certain probiotics don't make it they don't make it either because their cell wall is not prepared for their acidity because they were just meant to ferment milk and that's it and then we have a delicious product or because they're not in the right matrix and dairy is a perfect matrix because the moment you consume a glass of milk or a yogurt gets into your stomach and the pH rises immediately.

Speaker 3 Ah.

Speaker 4 And that makes the probiotics that are in a matrix like dairy survive better that

Speaker 4 30 minutes hour passage through the stomach.

Speaker 1 And is fermented dairy like yogurt is that easier to digest in terms of lactose too? Is there less lactose than just whole milk because it's been fermented? I've always wondered about that.

Speaker 1 Correct, yeah.

Speaker 4 So that's why the lactic acid bacteria, they transform the lactose into the lactic acid. And people that are sensitive to lactose, they typically can consume yogurts, but not necessarily milk.

Speaker 1 So yes, as we mentioned in the pharmology episode with cheese expert Kira James, some cultured dairy has low lactose because the the milk sugar has been gobbled up by what we consider the good bacteria.

Speaker 1 If you're sensitive and you get bubble tummy from milk products, the harder cheeses and the full fat or strained yogurt may be just fine for you.

Speaker 1 Although there are other proteins in dairy that can be a problem for folks. So if that's you or if you're entirely plant-based, there are non-dairy options as well with probiotic strains.

Speaker 1 I don't really care what you eat. Whatever fermented and cultured foods you like or don't like, you go for it.
I'm just here to learn about gut stuff, which we will continue to do in a moment.

Speaker 1 But first, a quick sponsor break, which is making it possible to donate to a cause of this time, my choosing.

Speaker 1 And this week we're donating again to the LA Regional Food Bank because one in four people in Los Angeles County experiences food insecurity.

Speaker 1 The LA Food Bank feeds hundreds of thousands of individuals every month and hunger affects people from all walks of life. especially now with the rising cost of food and everyday essentials.

Speaker 1 Just 25 bucks provides the equivalent of 100 meals for kids, seniors, and folks who need something to eat.

Speaker 1 But again, because of the sponsoring this episode, we are also able to donate to a second cause via givedirectly.org slash ologies, which is a special portal as part of December's Pods Fight Poverty Initiative.

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Speaker 1 It helps us do this. Let's take a quick break to thank our sponsor for this episode, Activia.

Speaker 1 When it comes to gut health episodes that we've done, we have gotten so many questions from listeners from like, is my gut health impacting my general health? What is stress doing to my guts?

Speaker 1 What's a prebiotic? What's a probiotic? Who's living down there? And what are they doing? So if you're having gut health concerns, Activia is here to help.

Speaker 1 Activia is a number one probiotic yogurt brand. Even before gut health was such a buzzword, Activia had been in the game for years.

Speaker 1 Activia scientists have been studying the microbiome and investing in research about that connection between food and probiotics in our digestive system for over two decades. They're on it.

Speaker 1 They're like, trend, try a lifestyle. This is what we do.
And taking care of your gut health doesn't have to be complicated.

Speaker 1 You can incorporate activia products, yogurts, yogurt drinks into your daily routine, adding some fiber-rich foods to your meals and staying hydrated.

Speaker 1 Those can be small wellness habits that really make a difference. Your gut is where it all begins.
Start with activia. Okay, how much should you be feeding your inner critters?

Speaker 1 Is there something too about doing it habitually, like not just having fermented foods or a probiotic like once every couple weeks?

Speaker 1 Is it better to have a habit where like, this is my morning yogurt and like grab it on the go and I'm kind of constantly refreshing? Is there something about that routine that helps the gut?

Speaker 4 Yes. I think it's same for any other food.
And I'm a proponent of a flexitarian eating diet, which is a diet that majority is made out of plants, but includes some animal products.

Speaker 4 But it's predominantly a plant-based diet. I don't know if you know, but most of the population is lacking fiber.

Speaker 1 Yes, I've heard this.

Speaker 4 So fiber is

Speaker 4 it's really important.

Speaker 4 And you have to consume it on a regular basis. And it's the same with probiotics because these are typically bacteria that don't stay in your digestive tract.

Speaker 4 So they pass, survive, transition, do their work in the gut, and then they go away.

Speaker 4 So it's better to consume on a regular basis.

Speaker 1 And now you have worked on the Activia brand and the science behind that. And I know I think it was like the first brand that I ever knew: oh, yogurt's got stuff in it that is good for you.

Speaker 1 That's good to know. And I feel like it's been kind of like this legacy of, oh, yeah, like get some good critters in your stomach.

Speaker 1 And I'm curious, too, like, how has the science changed since the launch of that? Do you learn more and more every year, especially since you just opened up this huge lab outside of Paris?

Speaker 4 Yes, it's true. So I think consumer needs change, right?

Speaker 4 And also, science evolves. I came here in 2004 to help prepare a little bit the public perception around bacteria because it was not at all what it is today.

Speaker 4 As you said before, everyone wanted to get rid of bacteria.

Speaker 4 It was, you know, that those, you know, alcohol wipes, bacteria is bad. You know, bacteria is bad.

Speaker 4 Even within the medical professionals that I talk to very often, it's part of my job, it was complicated to get folks to accept to consume bacteria.

Speaker 4 You know, they were fine in consuming maybe life inactive cultures or cultures, but probiotic bacteria is another stories.

Speaker 4 And more recently, a couple of months actually, we've incorporating prebiotics. That's a term we haven't talked about.
So it's not a probiotic, it's a prebiotic. So they kind of

Speaker 4 work kind of together in your gut

Speaker 4 to continue to support your digestive system and gut health. And the science on prebiotics came a little bit after the science on probiotics.

Speaker 1 What is a prebiotic usually? Is it a type of fiber? Is it kind of a substrate that the probiotics like to live in? Is it like giving them a nice like bedding kind of?

Speaker 4 It's a type of substrate and typically a fiber.

Speaker 4 One of the most populars is inulin. And you can get it from whole foods.
You can get it from onions, RTOs, asparagus, so some of the foods that contain prebiotics.

Speaker 4 But you can also have it from a concentrated form of chicory root as inuline, and then you can add it to the products.

Speaker 4 It is a source of fiber, but that fiber specifically grows what we consider the good bacteria in your gut. Ah.
So the good bacteria in your gut, like Bifidobacterium, they like that fiber.

Speaker 4 and they grow on that fiber.

Speaker 4 And that's one of the types of bacteria that helps balance out this diversity that I talked before.

Speaker 1 And how does that work? Let's get back to Dr. Xiao.

Speaker 2 Well, there, you know, when microbes digest fiber, they liberate these other molecules called short-chain fatty acids. And some of that can be used by the body as energy sources.

Speaker 2 Again, we thought that maybe the brain is detecting whether the microbe is extracting more energy out of these foods that our body can't digest, but can kind of sense and making choices based on that.

Speaker 2 So I think it was a nice kind of proof of concept that the brain can tell what the microbiome is doing.

Speaker 1 And another fiber question, soluble, insoluble fiber. Do our guts like a little bit of both or a lot of bit of both?

Speaker 2 I think that both have their different functions and would be affect the microbiome in different ways.

Speaker 1 Okay, so fiber. Part of the plant we can't break down because we're not cows.

Speaker 1 And according to the Mayo Clinic, we've got soluble fiber, which turns into this jelly substance in water, and that can slow blood sugar rises. It can lower your cholesterol.

Speaker 1 Where do you get this magic then? You can get it in carrots and beans, oats, peas, and psyllium husks, which you have to drink with plenty of water, okay?

Speaker 1 You take a metamuse. you chug some water with it.
Insoluble fiber, however, doesn't gel up. It just adds bulk and it also just keeps things moving.
And it's in beans and veggies and whole grains.

Speaker 1 If you're eating a Western diet, chances are you are not getting enough fiber of either kind. I'm not passing any judgment.
I'm just citing studies.

Speaker 1 And the 2019 Lancet study titled Carbohydrate Quality and Human Health, a series of systematic reviews and meta-analyses, crunched the numbers of nearly 200 different studies involving 135 million person years of data to find that having at least 25 to 29 29 grams of fiber a day reduced cardiovascular related death coronary heart disease strokes type 2 diabetes and colorectal cancer and if the inconvenience of cancer and strokes and dying isn't enough that's not enough of an incentive high fiber diets also over time can make it easier to fit into your pants that no longer button but yes start upping it slowly drink a lot of water with both types of fiber so yeah i think diversifying is the key because different microbes digest different types of fibers.

Speaker 2 And I think for the most part, just having a healthy community of microbes is what we all would be aiming for.

Speaker 1 Yeah. And Americans, we don't do great on fiber from what I understand, right? We're a little deficient in that area.

Speaker 2 Yeah, I mean, there's what the Western diet is just meant to be the high fat, high-sugar diet. And so, yeah, getting closer to Mediterranean diet, I think is

Speaker 2 something that would be a good thing.

Speaker 1 I love that we're also talking like in between Thanksgiving and the winter holidays here.

Speaker 1 Feed all your little babies some new friends. Get some fibery snacks and some water.

Speaker 1 Perhaps one of those snackies will be some kind of fermented goody as a treat for you and an emissary to your guts to say, hey, don't worry, this battle is going to be swift.

Speaker 1 It's funny that we have to kind of train our bodies like we would a pet.

Speaker 3 You know what I mean?

Speaker 1 Like we have to get ourselves used to it, which is why I think that it's not always easy for me to remember to take a probiotic every day, but it's very easy for me to remember to eat something yummy that's breakfast.

Speaker 3 You know what I mean?

Speaker 1 So I think it helps you like make a habit more. But is there anything that you have been researching that really surprised you? You've been working as a cell microbiologist for decades.

Speaker 1 Is there anything that was a finding that kind of shocked you?

Speaker 4 Well, I did my PhD on trying to understand the interactions between microbes and our own cells.

Speaker 4 This was back in 2001, and it was a very exciting moment at that time. There were not even techniques to be able to mix bacteria with our own cells in most of cell biology laboratories.
There weren't.

Speaker 4 It was something that you always wanted to keep apart. The cell biology lab is on that aisle of the corridor.
The microbiology lab is on that aisle because bacteria are going to contaminate the cells.

Speaker 4 And that was my passion is to put the two together. Because that's what's happening in our gut.
We're putting the two together. Now it's much easier.

Speaker 4 So I did explore a lot of that, the crosstalk between bacteria and the gut.

Speaker 4 I think this gut-brain interaction, I think it's super important, especially in these days, the way we're living, the stress, the going and running everywhere, you know, people are in a constant state of disturbances, right?

Speaker 4 And I have a passion for the gut brain access.

Speaker 3 So that would be my area.

Speaker 1 It seems like you're the right person for the job.

Speaker 1 I can see why you've worked here for like over 20 years. They're like, Miguel's our guy.

Speaker 1 What about something that you're really excited about coming up, especially with this, you know, with this new lab?

Speaker 1 And is there anything that you're just excited to get started on or to learn more about?

Speaker 4 Yeah, of course. I mean, personalized nutrition, food is medicine.
I mean, there's so many things that could pass through the microbiome

Speaker 4 and trying

Speaker 4 to

Speaker 4 design better foods. for people, improving people's health.
That's always been my passion. And I think food

Speaker 4 is a good way to do that. I am very passionate about trying to develop foods that address people's needs.

Speaker 4 And I didn't mention this, but Denone's mission is to bring health through food to as many people as possible. Populations are different.
We're a global company.

Speaker 4 Nutrition needs in India might not be the same as in the US.

Speaker 4 So we have to think about those differences when we're developing a product.

Speaker 4 Is fiber an issue everywhere?

Speaker 4 Is iron an issue everywhere? What's the role of a company like Danone in some of these public health issues? Type 2 diabetes, it's a very important thing.

Speaker 4 We actually obtained from the FDA the first qualified health claim for yogurt ever. associating consumption of yogurt with a reduction of the risk of type 2 diabetes.
Oh, wow.

Speaker 4 Yeah, after many years of research, many years of petitions and systematic reviews, the FDA granted this claim in 2024 and it was very exciting.

Speaker 1 And if you are seeking any new hobbies, how about looking up FDA documents such as March 2024's 51-page petition for a qualified health claim for yogurt and reduce risk of type 2 diabetes, docket number FDA-2019-P-1594.

Speaker 1 I'm going to add per our diabetology episodes part one and two with self-described diabetic diabetologist Dr.

Speaker 1 Mike Natter that watching added sugars is an important part of regulating blood sugar and blood sugar health. So as always, read those labels, folks.
There's a lot of science on them.

Speaker 4 We're also thinking about other types of options and products that could support gut health. And two of the products that we launched recently, one is a plant-based alternative.
So it's not dairy.

Speaker 4 It's under the brand Silk.

Speaker 4 And it's a plant-based dairy alternative that we formulated with pediatricians to get the right nutrition bundle to get into kids that are growing. And part of that bundle is fiber, is inulin.

Speaker 4 And because it's also important for kids' digestive health. Another one that has pre- and probiotics, which is also very important, is our happy family infant formula.

Speaker 4 So a lot of moms cannot breastfeed. So there's, of course, alternatives out there.
But we made sure that at least for babies who are growing these first 1,000 days are critical.

Speaker 4 And we know that one particular genus of bacteria is a keystone in the child gut. And if they don't have it, the consequences are not necessarily very good.
So, and this is a bifidobacterium.

Speaker 4 We add bifidobacterium and prebiotics to kind of mimic what you find in breast milk. So we prepare the kids' development of their immune system through the gut.

Speaker 1 I think it's so cool to be on the forefront of this and to be having like material benefits for people that are, you know, living at the same time as you is pretty cool.

Speaker 4 Yeah. And gut health, I think it's here to stay.
I mean, the trend is

Speaker 4 everyone is talking about gut health. And I don't, I TikTok, I have it for work, but you know, there's the gut talk.
There's

Speaker 4 so many

Speaker 4 people talking about gut health of all ages.

Speaker 4 It's not only only for an older person, which typically tends to have more digestive issues just because they don't eat as much fiber, they don't drink as much water, but even the younger people are concerned about their gut health.

Speaker 4 And this is not only about a yogurt, right? But we think about other options and where we can bring solutions that can improve everybody's life. And a lot of that goes through the gut.

Speaker 1 It's so great that you are able to take a passion that you've had since you were a kid i feel like you were pretty much born for this like you're in the right job it's got to be nice to go to work and be like yeah i'm definitely in the right job yeah you got to dust off that microscope just for fun i know i know i know exactly what it is uh it's launched a thousand

Speaker 1 thousand million yogurts um well thank you so much for doing this it's so fun to be in wife thank you so much yeah i have to visit you guys out in france yesterday with you out in france

Speaker 1 So ask professional people probiotic questions.

Speaker 1 And if you make good enough friends, maybe you can score a behind-the-scenes tour at a microbiome lab, she said, hoping to see a microbiome lab, perhaps in France.

Speaker 1 Thank you to the folks at Danon and Activia for suggesting the episode and for sponsoring this one, which means we can give generously to two causes this week, LA Regional Food Bank, and to give directly.org/slash ologies.

Speaker 1 You can see the links in the show notes for more info. We are at ologies on Blue Sky and on Instagram.
If you're looking for shorter, kid-friendly episodes, we have them in their own feed.

Speaker 1 Just search Smologies, S-M-O-L-O-G-I-E-S, and subscribe there. Thank you to Aaron Talbert for administering the Ologies Podcast Facebook group.
Avelyn Malik does our professional transcripts. Kelly R.

Speaker 1 Dwyer does the website. Noelle Dilworth is our prebiotic scheduling producer.
Susan Hale is multiple strains of managing director.

Speaker 1 And as a lacto to each other's bacillus, our editors Jig Chafee and Mercedes Maitland, lead editor of Maitland Audio.

Speaker 1 Also adding to the biome of this episode is the ever-beneficial Jared Sleeper of Mind Jam Media. Nick Thorburn tuned the theme music.

Speaker 1 And if you stick around until the end of the episode, I tell you a secret. This week, it's that right after college, I very reluctantly joined my then-boyfriend and his parents on a cruise.

Speaker 1 It's uncommon for me. It was the right thing to do diplomatically, although I hate sand and sun.

Speaker 1 But I got a sunburn so bad, I had to ask the boat kitchen staff if they could spare some plain yogurt to apply like frosting to my neck and my shoulders and my face.

Speaker 1 I'm still grateful to those people and all the billions of microbes that soothed me. Thanks, yogurt, and thanks for listening.
Okay, bye-bye.

Speaker 4 It's alive.

Speaker 1 Thank you again to the sponsor of this episode, Activia. If you're like me, gut health is fascinating.

Speaker 1 It's so interesting to think how much we're going to be talking about this more and more in the future, and also how it's on everyone's radar even more than it was when we did our first gut health episode like eight years ago.

Speaker 1 And the good news is, you don't have to be an ologist in order to discover more about how our guts work. Activia's research is not just stuck in a lab.

Speaker 1 They share tips and resources online to make your gut health easy to digest. You get it? Activia supports gut health.
They have deliciously smooth, creamy yogurts. I love them.

Speaker 1 They're packed with billions of live and active probiotics. Get them in your guts.
See for yourself at activia.us.com.