Prebiotics Probiotics and Postbiotics Explained

You're listening to this podcast, so I know you've got a curious mind. Here's a helpful fact you might not know yet. Drivers who switch and save with progressive save over $900 on average. Pop over to progressive.com, answer some questions, and you'll get a quick quote with discounts that are easy to come by. In fact, 99% of their auto customers earn at least one discount. Visit progressive.com and see if you can enjoy a little cash back. Progressive Casualty Insurance Company and Affiliates, National Average 12 month savings by $946 by new customers surveyed who saved with Progressive between June 2024 and May 2025. Potential savings will vary. It's Hannah. The podcast crew is off for the 4th of July holiday. But do not panic. I have something else for you to listen to today. Christina Quinn, who you just heard filling in here on the 7 yesterday, also hosts a podcast called Try This. I've told you about it before because I love it. She researches advice we can all use. Her latest season of Try This is about how to treat your gut better, as in how to cultivate a healthy gut microbi ome. I've learned a lot and hope you do too. So here's the first episode of the season. And then go look up try this to listen to the second episode. The third one is out next week. Here you go . Hey, welcome to Try This from the Washington Post. Try This is a series of audio courses to help you take on common challenges and learn something new without having to make a big time commitment. I'm Christina Quinn, and I'll be learning with you, Per Yuge . In this course, we're going to loosen our belts and unpack the mysteries of gut health, specifically the gut microbiome , because at the end of the day, what you put inside your body affects everything else. If you're new here, welcome. This course will have three classes, aka three episodes. So in this first episode, we're going to learn what the microbiome is exactly, and find out what all those microbes are really up to. In the second episode, we'll find out what happens to your gut microbiome when you start eating certain kinds of food . And in our third and final episode, we're gonna give you practical ways to make some changes without causing major upheaval to your life and your wallet. And we'll explain why you don't really need to take that probiotic. Okay, classes in session. Let's try this . When I have questions about anything having to do with digestion, I reach out to my favorite intestinal expert, Dr. Trisha Pasricha. I'm an instructor of medicine at Harvard Medical School. My second title would be I'm a gastroenterologist at Beth Israel Deaconess Medical Center. Do you want me to go get a white coat? I've got like I've got all kinds of props. I have a stethoscope, a white coat. I can go get it. No, no, no. I believe you. I know you're a real doctor. Dr. Prasricha also has a third title. She's a columnist here at the Washington Post. Her column is called Ask a Doctor. Yeah, I'm delighted. You you picked one of my favorite topics. I love everything about the gut, but the microbiome is like especially exciting. What is it specifically that excites you? I think it's so misunderstood. And yet the data is really thrilling and it gives me a lot of hope for the future. And there's a lot of emerging research because there's still a lot that we don't know, right? There's a lot that we don't know. I mean people have known about the bacteria that live in our bodies for decades and decades, like dating back to the early 1900s and even late 1800s. But in a way I think the part of it that's new is really understanding the role it plays in our disease and how we might manipulate it towards health. That part is still newer and still emerg ing . What exactly is the gut microbiome? Where is it? What's going on there? The gut microbiome that is what people have estimated to be around the order of about a hundred trillion different microbes that live in our guts. Our guts are not unique in our bodies in that in that they have their microbiome. Our skin has a microbiome, our mouths have a microbiome, but our gut microbiome seems to really play an important role in our health and in disease. And we're still kind of trying to figure out what those connections are. Well, I think when people think the gut. They just think of like their abs. In my case, super, super taut abs. Same . So so toy. No, I but the gut is actually, it's it's not just that. The gut, I think, is an all-encompassing term. We're we're usually talking about the colon, although bacteria live in the small intestine as well. And we're usually not talking about the stomach though specifically. Very few bacteria can survive in the acidic environment of the stomach. The stomach is the beginning of digestion, you know, and that's where the food starts to become broken down into tiny particles that then pass into the small intestine. And so by the time food has reached the colon, you know, and it has transitioned to what we might call poop, uh you've really derived all of the nutrients that you want out of it. Because the small intestine's job, which is in between the stomach and the large intestine or the colon, is to really absorb all of the nutrients and all of the good aspects of whatever you've eaten into the bloodstream and where it could be processed and used by the rest of your body. So it's really the waste that makes it to your large colon. But if you think about it, um, you know, waste is means like your body, the rest of your body, or other organs don't have a need for it, but what could make it there is fiber. Fiber is not digested, it's not broken down, it's not absorbed by the body, but it's a wonderful thing. And it's a wonderful thing that microbes live in our colon. They love fiber. As the old saying goes, one man's waste is another microbe's pleasure feast And then when they take that fiber in, you know, they produce these beneficial metabolites, one of which could be short chain fatty acids or other things. Short chain fatty acids are produced when gut bacteria ferment fiber in your colon, giving life to the cells that line the inside. They're part of a bigger picture that Dr. Prasricha spells out for us after the break. Get informed no matter where you are or what you're doing. Subscribe to Bloomberg News now and get news when you want it on your schedule. Think tech dominating our headlines. Another win for Donald Trump. A key inflation report. These are short audio reports, five minutes or less, that bring you the latest headlines with context 24 hours a day. Stay on top of the latest news from around the world. Get it on your smartphone. Subscribe to Bloomberg News Now on Apple Podcasts, Spotify, or anywhere else you listen . When it comes to the big questions, who you ask matters. From breaking news to politics that impact your life, to advice you can trust. Get answers you don't have to question with Ask the Post AI . Trained exclusively on post-journalism with clear sourcing. And if we don't know the answer, we'll tell you. Ask the post AI . Find it on WashingtonPost.com or in the app. Okay, so when we think about the microbiome, I think it's helpful to think about it maybe in three different parts, right? So there's these things called prebiotics, then there's maybe probiotics, and then there's these like post biotics. Let's start with prebiotics, which is non-digestible food. Fiber is a prebiotic. And we should be eating about 25 to 30 grams of fiber a day. But most of us aren't. All of us Americans, we're not getting enough fiber in our diet. Like so just take accept that. Whatever way you can increase the amount of fiber in your diet, you'll be better off. But if you really want to take it to the next level, what you want is the diversity in your diet. That means different kinds of fiber sources you would find in veggies, fruits, whole grains, and nuts. The microbes in your gut ferment that fiber, which fosters a super happy and diverse universe of bacteria. So all of these things contribute to the bacteria themselves and what kind of the composition, what strains and species these different bacteria are Probiotics are the so-called good bacteria that we associate with eating certain foods. If we're just talking about ingesting foods that we know contain beneficial bacteria, so that would be like fermented foods, kimchi, sauerkraut, active cultures like in Greek yogurt, nobody's ever gonna say that that's a bad idea. And and those things are known to improve the kind of overall composition of the microbiome and they're associated with decreased rates of gut symptoms. But here's the thing. Dr. Prasricha says the ideal form of a probiotic is the kind our body makes itself. And the way your body does that is by making certain dietary choices. This goes back again to eating good sources of fiber. Okay, so now let's dig into postbiotics. This is a lesser known word, but it's just as important. That's the other you know fancy word for what is the what is it that the b acteria are producing? What comes after that? And one of those things are short chain fatty acids. Short chain fatty acids like butyrate, you may have heard of, are these beneficial molecules that have an important role in our bodies. They can kind of help dampen inflammation. They're associated with reduced risk of all kinds of diseases, including cardiovascular diseases. And the kinds of postbiotics that your microbiome produces, they're different person to person, and they and they ultimately can be traced back oftentimes to what you are feeding that microbiome in the first place. So the more fiber you eat, and we're talking veggies, whole grains, and the microbes are just like nom nom nom nom nom I'm so happy. They love it. It's a buffet for them. And and the fiber, you know, just because it's not absorbed doesn't mean it's not benefiting you sort of personally earlier on in the process, right? Because fiber, it takes longer to digest. So some of the benefits you feel even before it hits the colon is that you might feel fuller longer, like you'll feel like you've had a more satisfied meal, as opposed to ultra processed foods that have this quick release of sugar, they're very easily broken down by the stomach, and then you're hungry again 15 minutes later. Right. Okay. So all the action really happens in the intestines. There's a lot of mileage in there, pun intended. There is. It's long, it's windy. The amount of time it takes for your food to become poop to to exit the body is different from the from me. It's different from the other people who might be watching this. Everyone takes a little bit of a a different length of time, but but it can't be on the order of days. And so it takes a long time to get absorbed first by the small intestine, all the nutrients, but then, you know, we have a little bit more control in when we poop. And so if we for whatever reason have decided like we can't afford to poop for the next five hours, we're in this middle of this podcast, we've got to focus. Um you could you could you could control that. You could hold it in. And that entire time, whatever you're you've not, you've decided to not excrete, your microbiome continues to feed off of. It sits there and your microbiome is loving it. And it's eating that fiber, whatever else you've given it to chew on, and producing more and more short chain fatty acids. It's a really nice visual. Yeah, and like right before lunch, it's perfect. That's great . So now that we've established that we are nothing more than mortal hosts to trillions of mic robes. We're going to see what we can do to make our tiny overlords thrive in a world that is stacked against us. But first, recap time. We humanoid bipeds are hosts to trillions of microbes that live in our gut , aka our intestines, namely our colon. That's where the party really is. And as Dr. Pastricha explained, it's helpful to think about the gut microbiome in three different parts: prebiotics, which is fiber that feeds the microbes and keeps them happy, nom nom nom. Then there's probiotics, which is beneficial bacteria from certain kinds of food with live cultures, like yogurt and kimchi. But if you eat a fiber-rich diet, you're creating your own good bacteria by keeping your gut microbes happy. Then there's postbiotics, which is a byproduct of the first two and has compounds that are absorbed through the colon where they can go on to benefit the rest of your organs. It's all connected, my friend.