Conquer Your Weight

Dr. Sarah Stombaugh: Before we get into the episode, I am thrilled to announce we are launching an online course, The GLP Guide. The GLP guide is a must have resource for patients who have been prescribed any of the GLP medications such as Wegovy, Ozempic, semaglutide, Zepbound, Mounjaro, tirzepatide, Saxenda, liraglutide. There are a lot of them and this course is available for anyone to purchase. We often hear from people who haven't been given much information about their GLP medications. No one has told them how to handle side effects, what nutrition recommendations they should follow, or what to expect in the longterm. And it can be really intimidating and simply frustrating to feel like you're alone in your weight loss journey. With the GLP guide, you'll get access to all of the answers to the most common questions for patients using GLP medications, not sure how to use your pen, struggling with nausea, wondering how to travel with your medications. We've got you covered for only $97 for one year access. This is an opportunity you do not want to miss. The course is launching on October 1st. For more information and sign up, please visit www.sarahstombaughmd.com/glp. You don't have to be on this journey alone. We are here to guide you. And now for today's episode, this is Dr. Sarah Stombaugh and you are listening to the Conquer Your Weight podcast. Announcer: Welcome to the Conquer Your Weight podcast, where you will learn to understand your mind and body so you can achieve long-term weight loss. Here's your host, obesity medicine physician and life coach, Dr. Sarah Stombaugh. Dr. Sarah Stombaugh: Hello everyone, and welcome to this week's episode of the Conquer Your Weight podcast. This is a long awaited topic. We are talking about the role of the microbiome, especially the gut microbiome and health and weight. And so I am so excited to bring in a guest, Dr. Katrina Coulter with me to talk a little bit about this because I am certainly not an expert, but she is an infectious disease specialist who lives in Colorado. Thank you so much for joining us today. Dr. Katrina Coulter: Oh, I'm so excited to be here. Thank you for having me. I think this is a really important topic that is becoming very popular and happy to talk about it. Dr. Sarah Stombaugh: Yeah, absolutely. I think really this is one of those topics that over the next one to two decades, I think our understanding and evolution of it is just going to change the way we both eat and practice medicine. And I am really, really excited about that. So before we dive in, tell us a little bit about yourself and how you came to be interested in the gut microbiome. Dr. Katrina Coulter: Yeah, so I did my medical school and training in Arkansas and chose to go into infectious disease because it's a really fun field where I get to see a lot of people get better. So then I moved out to Colorado where I'm originally from and started treating people inpatient and outpatient and would often get questions from my patients about their microbiome. So they would have a life-threatening infectious disease, they would need antibiotics. And some of my more savvy patients would say, Hey, well what is this doing to my microbiome? Is this killing it? Will it ever come back? What can I do to kind of offset this? And so I started talking to patients more and more about that and giving them tips. And then I just started finding that a lot of our conversations would veer towards food even with those patients that were not so interested in their microbiome. And so that gave me an opportunity to kind of educate them on the microbiome and tips that they could take to try to protect their microbiome as they went through this acute infection. And now I really see it as an opportunity to educate patients and also to discuss their diet. And I really found that a lot of patients didn't know what to eat or had a lot of confusion about what was appropriate to eat as they were recovering from an illness. And so I also really enjoy talking to patients about that. Dr. Sarah Stombaugh: That is so exciting, and I can't wait for us to get into some of this nitty gritty, but one of the things I've realized is that sometimes we have these conversations or you read articles and there aren't some of those fundamental and foundational pieces. I would love to start off with a super basic question. Tell us what is the human microbiome and then more specifically, what is the gut microbiome? What does that really mean when people say that? Dr. Katrina Coulter: So the human microbiome are these hundreds of trillions of cells that are symbiotic with us, but they're not made of us. So they are going to be bacteria, viruses, and fungi that exist on us and in us and really are there to kind of help us interact with our environment. So the gut microbiome specifically exists in our gastrointestinal tracts. So the way I think of it is we have a big open tube from mouth to anus, and that is full of bacteria, fungi and viruses. And it's like a community or some people think of it like a lost organ, and you want your community to be very diverse and everyone in the community has a role and they're all really important. And so keeping that community diverse and happy and healthy really helps our bodies stay healthy. And now we're learning translates into a lot of our diseases when this community is out of balance or when diversity is lost. Dr. Sarah Stombaugh: So it has a huge impact. And I just want to highlight that you said hundreds of trillions. I mean that is a huge number. And so when we think about the cells in our body that are us versus the cells that are sort of in or on our body that are not us, all of these bacteria and viruses and fungi, I mean that's a huge, huge number. Hundreds of trillions. Dr. Katrina Coulter: Yeah, we're outnumbered. We have more of the microbiome than we do of our own cells. So that just conveys how incredibly important they are to our existence and our health and keeping them healthy is really, really crucial to maintaining our own health. Dr. Sarah Stombaugh: And where do we get our gut microbiome? So when we think of babies being born and then how that changes or evolves over a lifetime, tell us about how it's both established and what are the influences that change that over time? Dr. Katrina Coulter: So the gut microbiome starts to become established immediately at birth. So babies are getting their microbiome from their mother, so they're picking some of it up as they're going through the birthing canal. And then as they're nursing, they're picking up more from their mother's skin and from the milk that they're making. And then it just slowly accumulates over time. But it turns out it's really important where you start at that has a big impact on your health for the rest of your life. And I'm not saying that to indicate that it cannot be changed over time, but there is a tendency for your microbiome to want to go back to where it started. So an infant starts out with a pretty non-diverse microbiome, and then as they go interact in the world, that's when they pick up more and more of these microorganisms. Dr. Sarah Stombaugh: Okay, amazing. Then I have to imagine there's all sorts of things, as you were saying earlier with your patients like antibiotics. Of course we know we're just setting off an atomic bomb in our microbiome. What are some of the big things that for good or for bad impact our microbiome? Dr. Katrina Coulter: So the foods that we eat have the biggest impact on our microbiome, but you could think of it as anything that we put into our mouth is going to have some sort of an impact on these bacteria. And so that may be a temporary impact or that may be a lasting impact depending on if you're putting that in temporarily or you are continuously taking it. So antibiotics is a great example. So one course of antibiotics can impact the microbiome for several months to years. And we have found that if we give antibiotics to infants, that impact is lasting throughout lifetime. And that's actually one of the things that we have found contributes to weight gain is antibiotic exposure early in infancy. Some other things that affect it though are things like NSAIDs, which would be your ibuprofen or your aspirin, they actually have an impact on it. Other foods in adults, we tend to take a lot of proton pump inhibitors, which are things like omeprazole and lanza prosol for acid reflux, and those shift the microbiome because we're killing the acid loving bacteria, which are actually really important and helpful. And then there's some things that you don't put in your mouth that can affect it, such as your sleep patterns and your movement or exercise patterns really have a big impact. Dr. Sarah Stombaugh: Wow. And as you've been alluding to, we see that these impact our health, they can really impact our weight. And I remember probably about a decade ago when I was at a conference for obesity medicine and they were talking about the role of the gut microbiome in weight, and there were some really interesting rodent studies that I'm sure we'll talk about as well as even just comparing what do the gut microbiome look like of a patient who does have obesity versus a patient who does not have that, and how there's these very vast differences between those. So tell us a little bit about what some of those differences are and how it impacts our health and our weight. Dr. Katrina Coulter: So this is a topic that's really we're gaining a lot of information on over the past 20 years. So starting about 20 years ago, we were finding in mice models that mice fed all the same diets. Some of them were found to be obese and some were lean and some were kind of in the middle. And so they started looking at the microbiome of these mice to see if there were differences, and in fact found that there were some differences between the obese mice and the lean mice in their microbiome composition. And so then they took it up to humans. And so we found some identical twins. And in medicine, we love identical twin studies because we know genetically that they're the same. And so then we can study environmental factors a little bit better. And so we found identical twins that had different body types, so some were heavy and they had a twin that was leaner, and they took stool samples from those twins, put them into mice that whose microbiome had been wiped out. And lo and behold, the microbiome, the human microbiome from the heavy twin resulted in a heavy mouse and the lean twin resulted in a lean mouse. So it became pretty clear that, hey, the microbiome is playing a role here in how we are putting on weight as humans. So we started digging a little bit deeper, and the short story is it's very complex. There are complex biological interactions going on, and we're not even anywhere near sorting it out, but we're learning some specifics. And one of the specifics is there seems to be two major Fila. So this is a way we divide things biologically. So you could think of it as two big families. So if you have your whole community in your GI tract, we have two big families that seem to have a lot of influence and the ratio of the number of inhabitants of those families seem to be a little different in people that have obesity. And so that's kind of our first clue is, okay, there seems to be a different makeup here where we're seeing more predominance of one type of family, but it's not that simple. It's not just, oh, there's too many of one and not enough another. We're also finding in people that develop obesity that there often is lower diversity in the microbiome. And something that's kind of interesting about these different families of bacteria is that the ones that are more predominant in people that have issues with weight gain also seem to be the bacteria that are better at extracting energy from food. And so from an evolutionary standpoint, this would convey a benefit. So if you were in a time of food scarcity and you had more of these bacteria that could extract energy better from food than the other bacteria, you would be more likely to survive. I think that's really interesting when you look at it from that standpoint is these play an important role, we need these bacteria, but something else down the line is going awry. Dr. Sarah Stombaugh: Well, and I really want to point that out because I remember the first time that that was conveyed to me this idea that we think about calories and you think about any food, whether it's a donut, whether it's an apple, and we have these food labels that say it has X amount of calories in it. And the way that we determine calories is literally by incinerating a food and seeing how much energy does it take. Calorie is just a unit of energy. And the wildest thing is that a, let's say a 300 calorie donut, for example, that one person may eat that donut and extract nearly all 300 of the calories from it, where another person may extract a fraction of the calories from it, part of that donut goes undigested and then is just excreted as stool and never even used as energy, which is just unbelievable. Dr. Katrina Coulter: Yeah, it's really fascinating how we've evolved to manage what we have in front of us and to get what we need from it and kind of dump the rest. And so we're seeing these big changes in our food systems that have really been happening over the past 50 years, and one of them is the process or the ultra processed foods where we are manipulating our foods more and more from the way we would find them coming from the earth into something that's going to be shelf stable to last for a long time into something that's going to be favorable to the taste palette. And that's also going to tell our bodies that, no, we're not full yet. Eat more and more finish off the whole bag of chips. And so these changes in the food system are affecting our microbiome and I think are contributing a lot to the rises and obesity and other chronic diseases that we have seen skyrocket over the last 50 years, especially in developed nations. Dr. Sarah Stombaugh: And I think there's this, correct me if I'm wrong, but sort of this chicken and the egg thing by which the foods that we eat are driving our microbiome, but then our microbiome can lead to maybe craving certain foods or interest and desire for certain foods. Am I understanding that correctly? Dr. Katrina Coulter: You're totally right. Yes. So when you eat more sugar, you feed the bacteria that loves sugar, and so they proliferate, they grow into bigger colonies, and then they signal to your brain, we need more sugar. And so then you have these cravings for sugar. And so it is really interesting. It's kind of this negative feedback loop where you're selecting for these certain type of bacteria and then they're telling you keep feeding me. Dr. Sarah Stombaugh: And so how do we break this cycle? I mean, it seems like, I think even a lot of my listeners are probably like, oh shoot, I'm recognizing that. Or we hear things like food noise, for example, which we think about the role of gut microbiome in food signaling as you're describing, when someone is dealing with these cravings for food, maybe we've recognized there needs to be, or it would be beneficial to have a shift in microbiome. How do we do that? Dr. Katrina Coulter: I think the first step is just awareness that this is happening and awareness that a lot of these foods that most of us were raised on and that we tend to reach for as parents because of convenience are really not as healthy for us as we may have been led to believe, and that they actually might be causing a big part of the problem. And so again, going back to these kind of processed foods, I feel like there's been a lot of marketing throughout my life. It's, oh, eat this granola bar, it's so healthy for you when really it's a lot more unhealthy and having a much bigger impact than we realized. And some of this is because our scientific research is taking a little while to catch up to these effects of the ultra processed foods. We're just now really starting to see the research that's telling us that, hey, these are actually having a much bigger impact on our health than we had realized. So I think awareness is that first step and awareness of the impact it has on the microbiome. And then you can start being more and more mindful about the food choices you make. Another way to think of it with the signaling molecules is, and what you're alluding to is what we call the gut brain axis. And this is really cool. This is where the microbiome and the products it makes, or the common words you may hear now is the postbiotics, which are the signaling molecules that the bacteria make, are molecules that travel up to our brain through our vagus nerve and they impact how we make decisions. And so during certain times of stress, you may have more of a signal coming down from your brain or your gut may be signaling up to your brain, Hey, I'm hungry. I need certain types of food. And you can affect how that signaling is happening by the food choices you make. So by making better food choices, you are going to get a better signal to the brain and then you are going to close that feedback loop, if that makes sense. Hopefully I'm not losing everyone here. Dr. Sarah Stombaugh: No, I love that because we think about this chicken and the egg thing and it does go both ways. And so recognizing while, okay, my body is signaling something, is that signal in line with my goals or is it because of an event that I'm going through or just a sort deranged microbiome that's gotten out of whack for whatever reason? I'm curious, you're alluding to food choices that may be more supportive of a healthy gut microbiome. Tell me about what type of food choices are supporting that healthy gut microbiome? Dr. Katrina Coulter: So I'm going to use another buzzword here that I think people are starting to hear a lot, and that's prebiotic. And so there's all this talk about prebiotic probiotic and post biotic. And so prebiotic fiber or it is fiber, it's what our microbiome likes to eat. And some people might think of it as, is it a pill I buy? And it's absolutely not a pill that you buy, it's the food you eat and it's fiber, and we don't get enough fiber in our diet as Americans. And going back to the ultra processed foods, they are replacing a lot of our fiber. So instead of grabbing an apple now as a snack, you may grab something else that has a lot lower fiber content. So we're starving our microbiome essentially by eating ultra processed foods. So if you could add one thing to your diet to really help your microbiome, it would be fiber and fiber we find in fruits and vegetables. Dr. Sarah Stombaugh: Absolutely. And grains in their whole form. Is that a fair assessment? Dr. Katrina Coulter: Yes, absolutely. Yes. Thank you. Dr. Sarah Stombaugh: Yeah. And what about fiber supplements? So someone's like, I take Benefiber or MEUs or cilium husk. How do those play or not play a role? Dr. Katrina Coulter: I think they're a helpful adjuvant, but they should not replace your dietary fiber intake because in addition to the fiber that you're getting from, say, eating an apple in which you're getting two types of fiber there, you're getting the insoluble fiber from the peel, you're getting the soluble fiber from the actual inner part of the apple, and these feed different types of bacteria and they play different roles in the microbiome. You're also getting phytonutrients. And so when you take a fiber supplement, whether it be Metamucil or cilium husk or whatever it is, you're not getting those phytochemicals as well. And those are a lot of our vitamins. And those also nourish the microbiome and those bacteria. Dr. Sarah Stombaugh: And so a supplement may be valuable, but it's just that it's a supplement. It's not the whole shebang. Dr. Katrina Coulter: Exactly. Exactly. And the same thing. I was going to say the same thing with probiotics. So a lot of people ask me, which probiotic should I take? And they're referring to a pill form or a capsule. And while that may be helpful in certain situations, if you are not eating the prebiotic fiber, the probiotic is wasted. It's not going to stick around in your community because it doesn't have the food it needs to eat. And so we really need to understand that you can't get your meal from a pill, everything we need to eat real foods. Dr. Sarah Stombaugh: Absolutely. Well, and what's interesting to me too is when we look at what is in the probiotics, and if you go to any pharmacy and you pick up a bottle of probiotics and pick up a couple bottles and read the labels, we tend to see some of the same lactobacillus. And tell me about how those things came to be in probiotics. Dr. Katrina Coulter: So these are isolated from bacteria, different species or families of bacteria that we found to be helpful. But what you'll notice on those labels is that there's usually only one type of bacteria in there in your supplement, and that may not be what you're missing. And so supplementing the same thing over and over is not necessarily going to solve your problem. You really need this whole diverse array of these different bacteria. And so that's why another reason why probiotics, they can be helpful in certain situations, but they're not the answer to maintaining a healthy microbiome. Dr. Sarah Stombaugh: Absolutely. Well, and one thing, I know this on a very surface level, so you might need to expand this a little bit for me, but when we think about all of our bacteria and we think about aerobic versus anaerobic, so bacteria that can be exposed to oxygen in the air versus those that oxygen would be toxic and they would die in the presence of that. When we think about our gut from our mouth to our anus, it's a long right? We have 20 some feet, correct me if I'm wrong, of small intestine, and there is a huge amount of the inside of our body that is never exposed to air and oxygen. So there's some bacteria in my understanding that our living is sort of deep within our small intestine, deep within our core that we haven't even as a scientific community identified because it's so challenging to study them. Is that a fair understanding? Yes. Dr. Katrina Coulter: Yeah, that's absolutely right. As we get deeper into the intestines, most of the bacteria are anaerobic or non-air breathing, and that's absolutely true. We have not identified all the different species that are in there. Dr. Sarah Stombaugh: And so when we think about supplements, for example, while there may be some value to taking a supplement, you are probably missing, you're certainly missing all these fully anaerobic bacteria, but you're probably missing a whole lot. We think of those trillions, hundreds of trillions, as you said, of species make up our microbiome. And so taking even, I've seen a handful of supplements that'll have 10 different probiotics or bacteria species making up this probiotic. And even that is still a teeny, teeny tiny fraction of the whole thing. Dr. Katrina Coulter: Absolutely, absolutely. Yeah. And just one other thing to consider is that probiotics are not FDA regulated, and so there's really no guarantee that what it says on the bottle is actually what you're getting. There's been some kind of egregious cases where there's been some made up names of bacteria on the bottle. Oh, no. And most people aren't going to know. I mean, you can just come up with some crazy long scientific name and people are like, okay, that sounds good. But yeah, there's very little oversight on the probiotic industry. And so you don't know if you're getting what you're getting and you don't know if that's actually what you're missing or what you need. And so again, they can be helpful in certain situations, but I think that we're in a society where we want the pill to fix the problem, and this is a little more complex, and you have to be more committed to maintaining your microbiome and taking care of it. Dr. Sarah Stombaugh: Absolutely. Well, I think the evolution of understanding of that too from a broader public health standpoint, thinking about our food supply and how we're supporting people with making choices and making easy choices that are in line with supporting this healthy gut microbiome. So yeah, I love that. Tell me, in my line of work, we're often using medications to support people in their weight goals, and particularly the GLP-1 medications, for example. What role would a medication like that have on the gut microbiome, if any? Dr. Katrina Coulter: Yeah, the GLP-1 is really interesting because it stands for glucagon-like peptide one. And this is made in our intestines. This is made by our intestinal L cells naturally in our bodies, and bacteria signal our body to release this GLP-1, and then it goes up and it acts on our brain and tells us, Hey, we're full. So what we're finding and why I mentioned in the beginning that in the makeup of the microbiome in people that tend to be overweight, just being a ratio imbalance is not. The whole story is because what should happen is we get food, we extract the energy we need from food, and then we stimulate this GLP-1 release from the intestinal cells, and our body's like, okay, I've had enough food. I'm good. You don't need to eat anymore. And we're finding in people tend to put on more weight that they have lower GLP one in their system, and so they have the bacteria that are extracting more energy, but then it's not signaling as to, Hey, we've got enough, we can stop there. And so these GLP- 1 gonists being supplemented are then telling our body, okay, hey, now you don't need to crave that food because you've got enough energy and it also affects insulin release. So a big question in my mind was, well then what does it do to the microbiome? Does it mess it up? And what we've actually found in humans that get the GLP one agonist that their ratio of bacteria in their microbiome tends to shift more towards those that we see with lean people. So we're seeing a little bit of microbiome change. We're not seeing a big change in the energy extracting bacteria, but we're seeing some of the other smaller players start to increase. And so a little bit of increased in the diversity. Dr. Sarah Stombaugh: Okay. That's really exciting to hear because I have to imagine that's really probably pretty new research. I actually haven't heard any of that before. Dr. Katrina Coulter: Yeah, it's fairly new research, and it begs the question, what then happens if you stop taking these GLP-1 agonists? Does your microbiome go back to the ratio it was before? Or have you changed your eating habits now? And so you're able to support this more lean microbiome profile? We're actually seeing with some of the surgical interventions for weight management as well, such as the RU and Y or the gastrectomy that the microbiome tends to change after those interventions also. Dr. Sarah Stombaugh: And I actually heard a really interesting speaker talking about the, which antibiotic was given at the time of surgery, for example, and then how that affected results of bariatric surgery as well, which was really interesting. And so we think about this role of all of it plays a role, so there's all of these really different moving pieces, but thank you for sharing that piece with the GLP because I think these medications are amazing and have been really life-changing for people who've been struggling with chronic obesity and have diet and exercise alone has not been supportive of their health goals. And so being able to use medications like these to help support that GLP-1 signaling is actually a perfect example of that gut brain access where a signal that is created in our gut is then triggered in our brain to signal that pathway or that decreased hunger pathway. And so it's really exciting to hear that we're starting to see that shift in bacteria. And I think as we'll see some of this stuff play out with what does long-term weight maintenance look like for people who have continued versus discontinued these medications? There's a lot of ongoing studies there. And it's really interesting because overall, while if you look at the population curve of people who take the medications and then stop them, most people will regain rate but not fully. When you start looking at an individual level, there are patients for whom they actually nearly maintain their entire weight loss for patients who regain the whole thing. And so it makes sense that there may be other pieces like the gut microbiome that are helped to signal what happens there. Dr. Katrina Coulter: And I think also a piece that's really important and something that you focus on that is crucial is also the mindset piece of it. It's not just a fix with a medication, but there's also a mindset of how you're eating and why you're eating and working on that and evolving from that perspective is crucial to maintaining weight loss after these interventions have been discontinued or tapered off or wherever you go next Dr. Sarah Stombaugh: With. Yeah, absolutely. And I think that's the piece that working with, I think right now, I'm so afraid of, you can have people fill out forms online and get medications delivered to your doorstep, and I want to make sure, honestly, whether we're talking about the treatment of obesity or we're talking about many health conditions, do you have that comprehensive support to be able to support your overall health And not just in anything. You don't want to be taking just a single treatment. You want to be really looking at how do we comprehensively support someone in their health goals with this? And so yeah, really cool to see how that will play out. Dr. Katrina Coulter: Yeah, absolutely. And from my perspective as an infectious disease doctor, it's the same when I'm prescribing an antibiotic. I want to make sure that I'm not just, oh, you have a UTI I'm treating your symptoms, but that we're actually talking about why are you getting these urinary tract infections and what preventative interventions can you make in your life so that you won't be needing antibiotics repeatedly. Dr. Sarah Stombaugh: Yeah, absolutely. Okay. So when we think about this field, I mean, as we talked about over the next decade, two decades, I think it's going to have a really big impact in our understanding and treatment. Are there things we're already starting to see here about, let's say fecal transplants, for example, for the treatment of C. diff? We haven't gotten into that at all. Are there things that we can do that that would be supportive of patients and their health and weight goals? Dr. Katrina Coulter: So there are some studies in which that's been done and whether or not we'll see that reach primetime or not is yet to be determined, but that certainly is an avenue that's being looked at and beyond that. Now, there are some stool capsules made by Nestle, which is really funny to me. If there are chocolate, chocolate or is it poop? Yeah. But that may be a modality we see in the future as a way to try to reset somebody's microbiome. What I hope to see is that we really start to recognize the role our food systems are having on a lot of our weight gain, and both the consumer, but also the producers are more responsible in some of the food that's coming out and how it's impacting us. Dr. Sarah Stombaugh: Absolutely. And so while I'll say fecal transplant is, as you said, it's basically a capsule of stool or poop, and it's very, maybe not very commonly, but it has been used in the situation of C. diff infection, so a bacteria infection that many of us have C. diff, but in certain situations where other bacteria have been suppressed that C. diff can take over. And in that over dominance can be bad when that happens and people can be very sick from c diff infections and patients who are not responding well to then other antibiotics to support that. Sometimes that, I won't say last ditch effort, but a very commonly last thing that's done is something like a fecal transplant or basically someone who has this now C. diff predominance is taking a pill that has literally stool in it from another patient in order to help treat and really replace their microbiome. There's a lot of challenges that come with that, though. I can only imagine in terms of regulation of that, in terms of what are you getting from the donor? Is that donor otherwise healthy or is that donor going to change over time? Right? Because if that donor travels or takes bacteria or antibiotics themselves, for example, there's a lot of evolution. So yeah, I have to imagine the bringing something like that to market would be, there's a lot of steps. I'm not sure if we'll see that get approved. Dr. Katrina Coulter: Yeah, you always have to think about other infections that could potentially be transmitted when you're taking something from one person and putting it into another person. And so that's certainly where a lot of the regulatory oversight is, and it is very effective for C. diff. And as you mentioned, I think of it as a last ditch effort as well, but it usually is the last step because it is a very effective treatment for that particular condition, which is a big imbalance of the microbiome usually precipitated by antibiotic use. Dr. Sarah Stombaugh: Absolutely. And in that situation, we're talking about really a pretty, you could speak better to the mortality of that, but C. diff when it's untreated has a very high mortality. And so the idea of using something like a stool transplant is the benefit far outweighs the risk of that when you're that far down the treatment regimen. Is that a fair assessment? Dr. Katrina Coulter: That's true. But it is interesting about C. diff, as you mentioned, about 20% of us do have this Clostridium difficile bacteria in our intestines, and it's being kept in check by all the other bacteria that are there and doesn't become problematic until something has tipped the balance, such as a course of antibiotics or antacids. If you're on a proton pump inhibitor, that is definitely a risk factor for developing it. But not all people that even develop clinically significant C. diff get incredibly sick, and that's likely because they have robust and resilient and diverse microbiomes. So I've seen the whole gamut of disease from somebody just having diarrhea one time, and then it's kind of resolved on its own to people dying of toxic mega colon from C. diff. And so if I can plug a reason why you should be taking care of your microbiome, it's because you want to be resilient against these infectious conditions that we can't predict things going around like norovirus. Some people have a very mild case of norovirus, some people are miserable and out of work for days or weeks because of norovirus, and we're going to encounter those things in the world and how diverse and healthy our microbiome is going to dictate how we respond to that insult. Dr. Sarah Stombaugh: Okay. I love that because this is such a real world example of we know exactly how this can play out. Certainly with weight, with many other health conditions, we know that it impacts it, but we don't know exactly how, we don't have the exact answers, but there's a lot of, especially with these infectious health situations, we've seen it play out over many years or decades even. And so such a perfect example of why we need to support our gut microbiome. Dr. Katrina Coulter: Absolutely. Yeah. Dr. Sarah Stombaugh: Okay. Amazing. And so with where we're at right now in 2025, things like probiotics may have a small role, particularly for people who've recently taken a course of antibiotics, for example. But generally, the best way that we can support our gut microbiome is with a diverse diet full of fiber. So fruits, vegetables, grains in their whole form, really real food. So can we eat real food that is signaling, satiety and our body and then supporting that healthy gut microbiome? Is that a fair assessment? Dr. Katrina Coulter: That is a fair assessment. And then I would like to mention one other type of food that I really encourage my patients to try to get into their diet on a daily basis or at least three or four times a week. And those are fermented foods. And so these are going to be the foods that contain live active bacteria or where live bacteria or yeast has been used to make the food. And so we're thinking of things like yogurt, kefir, sourdough bread is a fermented food. Kombucha has become really popular. It's a fermented tea. Kimchi is a great one that I really enjoy. A lot of people don't like these kind of fermented vinegar foods, but they contain the prebiotic, the probiotic, and the post biotic. And so you're really getting it all in one food. And if you can add them to your diet on a regular basis, you are really constantly replenishing your microbiome with healthy bacteria that are going to help you. You're going to get the postbiotics, which are these signaling molecules, and so it's kind of like an all-in-one bonus meal. Dr. Sarah Stombaugh: Yeah. Okay. I love that. And I'm going to ask a question that I have to imagine a lot of people will be thinking if you haven't been eating a lot of these type of foods, whether it's some of the fermented foods or even certain fibers that can really trigger gas and bloating, tell me, is there anything people can do in order to reduce that? Because certainly gas and bloating can be a very common thing if you weren't eating a lot of these foods and then you bring in a lot of them. Dr. Katrina Coulter: Absolutely. My best advice is just take it slow. So don't just decide all of a sudden I am going to have beans for my meal every single day because your intestines are going to take some time to adjust. And so think of it as you're growing these colonies slowly, and so you want to introduce these foods a little bit at a time, notice how you feel maybe time when you eat these foods to not coincide with when you're going to give a big public speaking event or a big social event. So kind of time 'em when you're going to be home and can be on your own and see how your GI tract responds to them. But as you ramp them up, the bacteria that need these foods are going to become more prominent and your intestines are going to tolerate them better and better. Dr. Sarah Stombaugh: I really wanted to ask that question because I see that come up a lot where people have just made a huge shift in their diet and then they eat a lot of these prebiotic foods and probiotic foods and all of a sudden they're just gassy, they're bloated, and they're like, my body doesn't tolerate this, and they stop. And so just knowing that's totally normal that that would happen. And so take it low and slow, as you said. Dr. Katrina Coulter: Yep. That absolutely does. It happens to everybody. And one way to look at it as is when you are feeling gassy, that's actually your bacteria signaling to each other. And so it is a sign of good digestion, so it's not necessarily a problem, but obviously can be very uncomfortable and it can be embarrassing depending on the social situation. And so just be kind of thoughtful about this and expect that it's going to happen and then take it slow. Dr. Sarah Stombaugh: Okay. I love that advice. And let me ask you, I have a feeling we could talk all day long, but because we don't have all day long, is there anything you haven't yet had a chance to share with my audience that you think is just really important for them to understand in this conversation about gut microbiome? Dr. Katrina Coulter: I think we've hit on all the high topics, but I would just like to say that this is something that you can modify, and that's what I think is so cool about it, is that unlike genes which you are born with, and there are some ways that we can modify which genes are expressed and are not, but the microbiome is something that you have control over. And so you can make healthy choices and see the positive effect from it. And it's not going to be immediate. It's probably going to take about six to eight weeks to really see some changes in the way you feel and your mood and maybe how you're holding on to weight. But it is something that you can continue to work on over time. And if you splurge on a donut or a bag of cookies, it's not the end of the world. It's not like you can't go back and there's irreversible damage. So just know that it's something that you are going to be working at your whole life. Dr. Sarah Stombaugh: Absolutely, and I love that you pointed that out because we don't have to feel like, okay, I'm doomed. I don't have it. Right. There are things we can do to gradually shift our microbiome in the direction that we want. Okay, amazing. And tell us, if people are interested in learning more about you and the work that you do, where can they find you? Dr. Katrina Coulter: Right now? I have a YouTube channel where I'm trying to get this information out and just educate the public about positive choices in our diet. And that is Katrina c dash md and that's on YouTube. I will have a website coming soon, but I will announce all of that on the YouTube channel. So come check me out over there. Dr. Sarah Stombaugh: Okay, amazing. And we will definitely make sure to put that information in the show notes. Thank you so much for joining me today. This has been really fun. Dr. Katrina Coulter: This was a great conversation and I'd love to carry it on sometime in the future. Thank you for having me. Dr. Sarah Stombaugh: Yeah, absolutely. Well, and I love that you invited yourself back because as this is an evolving field, we are going to have more questions for you. So if any of my listeners have questions, you can always email those to us at info@sarahstombaughmd.com, whether those are for me in general or for Dr. Coulter, and I would love to have you back. So thank you everyone for joining us for today's episode. We will see you all next time.