“Test. Don’t guess.” One of the tenets of functional medicine is you have to address the underlying cause of a problem in order to get the best result long term. You can’t address the underlying cause if you don’t know what it is. If you just assume that it’s yeast overgrowth based on some symptoms, that’s not really adequate in terms of making a diagnosis because the symptoms of fungal overgrowth are extremely nonspecific. Find out what you’re dealing with because the treatments will differ.

Note: The Prescript-Assist supplements discussed in this article are no longer available. Please click here to learn more about a substitute, the Daily Synbiotic from Seed.

In this episode, we cover:

2:06 What Chris ate for breakfast

5:20 Is it really yeast overgrowth?

10:28 Diet for treating yeast overgrowth

21:51 When to use antimicrobials

24:15 Restoring and rebuilding the gut

Steve Wright: Good morning, good afternoon, and good evening. You are listening to the Revolution Health Radio show. I’m your host, Steve Wright, co-author at SCDlifestyle.com. Revolution Health Radio is created for you and by you. It’s also brought to you by 14Four.me. 14Four.me is a 14-day healthy lifestyle reset program Chris has put together. Based on just working with hundreds of people and interacting with thousands of people on his blog, he has really realized, much like I have, that it’s just really hard to implement things that we talk about when it comes to healthy habits. Sleep, diet, exercise, and stress are all major components that we talk about on the show all the time. But to do them all at one time is pretty much guaranteed in the research literature, unless you have someone holding your hand, you’re going to fail. So 14Four.me does that in 14 days, where step by step, day by day, Chris actually walks you through how to do all of these healthy habits at the same time, so that you can do 14 days of really resetting, getting back to zero, and hopefully starting your new year off or whatever month it is right. If you haven’t checked it out yet, go over to 14Four.me and do that now. As always, with me is integrative medical practitioner, healthy skeptic, and New York Times bestselling author, Chris Kresser. Chris, how are you doing today?

Chris Kresser: Good, Steve. How are you?

Steve Wright: I’m pretty pumped, man.

Chris Kresser: All right.

Steve Wright: It’s a good day.

Chris Kresser: Good day. Yeah, it’s a beautiful day here as well. We have a good question. It’s one we get a lot and one that I think a lot of people are going to be interested in, and one that there are quite a few amiss and maybe misconceptions about.

What Chris Ate for Breakfast

Steve Wright: Before we get into that though, Chris, we can’t go too many episodes without finding out what you were eating before the episode started.

Chris Kresser: Right. Not much to report today: coffee and cream (edit: usually I drink bone broth too). You know, we record the episodes a few weeks before they’re published, so this is actually right before Christmas. Lots going on. I’m getting on a plane soon to go visit family. There’s a lot happening. It’s a perfect opportunity to do some intermittent fasting. So that’s what I did today.

Steve Wright: Awesome. Yes, and that’s why my background is slightly different than the white walls. I’m at my parents’ house here in Michigan.

Chris Kresser: Nice. You don’t have the impressive phone cave that I have and that you normally have on.

Steve Wright: No, no. The audio quality is not going to be quite as well, but the background is a little bit more interesting.

Chris Kresser: Better scenery.

Steve Wright: Exactly.

Chris Kresser: Cool. Let’s give this question from Nada a listen.

Nada: I have a question for you about yeast overgrowth. I’ve been on the GAPS diet for about six months now. I’ve gotten better, but still having some symptoms, so I went to a holistic practitioner. She did the Metametrix test, the TRIAD test. It confirmed I had a yeast overgrowth. She wants me to start adding potatoes and things like that back into my diet, but I’m really scared to because I know that disaccharides are hard to digest. So I wanted to know what your recommendations are about yeast overgrowth, treating Candida, and sealing the gut barrier.

Chris Kresser: All right. Again, this is something that so many people are interested in. If you do some searching for Candida or yeast overgrowth on the Internet, you’re bound to just get bludgeoned with a crazy level of information. And a lot of it’s pretty kooky and quacky and unreliable. So I’m glad to have a chance to address this. I mean, we’ve talked about it here and there in the past, but it’s good to just do a really focused episode on it.

Steve Wright: Before you dive in, Chris, I just want to let everybody listening know that if you’d like to have your question answered, go to ChrisKresser.com/podcastquestion. Go there.

Chris Kresser: Hijack the show.

Steve Wright: Yeah, hijack the show. You want to talk to us? You have to go there.

Chris Kresser: Thanks for reminding me. It’s so great, as Steve said, to be able to make this show super relevant to you and your needs, and what you want to hear about. That’s really how it works. Definitely head over there and record a question. We want to hear your voice.

Is It Really Yeast Overgrowth?

All right. I’m going to break this down into a few different categories. The first is not necessary based on what Nada said in her case. Or I’m assuming it’s a her. Sorry if it’s a he. But I want to point this out because it is something that often gets overlooked. It’s important for the general population that’s thinking about this. That is the question—is it really yeast overgrowth? One of my pet peeves is when I hear people say, “Oh, I’ve got yeast overgrowth,” or, “I’ve got Candida,” or, “I’m on a Candida diet.” I ask them, “How do you know that you have Candida?” And they say, “Well, because my tongue is white and I spit into a glass of water, and the saliva…” You know, all of these sorts of tests or even just symptoms that are not reliable as a means of diagnosing yeast overgrowth. There’s always an assumption made that it’s Candida, which may be, but it could be any number of other fungal species. It’s really important to test. I’ve always said on this show that we’re a big believer in the saying, “Test. Don’t guess.” Because one of the tenets of functional medicine is you have to address the underlying cause of a problem in order to get the best result long term. And you can’t address the underlying cause if you don’t know what it is. If you just assume that it’s yeast overgrowth based on some symptoms, that’s not really adequate in terms of making a diagnosis. That’s because the symptoms of fungal overgrowth are extremely nonspecific. What that means is there are things that could be caused by any number of other conditions that aren’t yeast overgrowth: fatigue, digestive discomfort, muscle aches, brain fog, low libido, hormone imbalance, skin rashes. These are all symptoms that could be attributed to Candida or fungal overgrowth, but they could also be caused by a parasite, SIBO, general dysbiosis. Or it could be something entirely different, like chronic infections such as Lyme disease, coinfection or a biotoxin-related illness, like a mold problem, exposure to a water-damaged building, or even potentially an autoimmune condition or a thyroid condition. And those are not all mutually exclusive. You can have fungal overgrowth and those conditions, and they often do go together.

But the point is, you need to find out what you’re dealing with because the treatments will differ. I treat fungal overgrowth slightly differently than I treat SIBO, for example, or general dysbiosis or a parasite. Certainly, I would approach autoimmune disease differently than I would approach fungal overgrowth. There are pretty good tests for fungal overgrowth at this point. The best ones are stool tests through Genova (formerly Metametrix) or Doctor’s Data that can detect fungal overgrowth in the stool. You can get a urine organic acids test from Great Plains Laboratory. It’s a good one. Then the Genova Organix Profile is also a good one. They will detect organic acids, which are by-products of fungal metabolism in the urine. If they’re elevated, it’s a sign that there may be a fungal overgrowth. You can also test antibodies to Candida in the blood. So there’s a range of ways that you can get some objective data on whether you have Candida. In this case, as I mentioned, Nada already had the Metametrix test. I’m assuming she means stool, but she could mean the organic acids test as well, I’m not sure, and confirmed that there was a fungal overgrowth. It seems like she’s covered that base.

Steve Wright: Yeah. I think it’s really important, just to kind of reiterate what you were saying there, that a lot of the general symptoms or things that we notice in our lives when we’re sick could be attributed to yeast overgrowth, but they could be attributed to lots of other things. I don’t know what your experience has been, but my personal health history, as well as the people that I’ve worked with and the thousands I’ve talked to, typically, it’s not just yeast.

Chris Kresser: Yeah.

Steve Wright: So this idea of not testing and sort of just—or going off just one test and assuming, “Hey, I found something. That’s it. That’s the one singular root cause.” I think it’s really important to make sure people understand that that could set you back. That sort of belief could set you back quite a bit and have you wasting a lot of time and money.

Chris Kresser: Great point. I agree. I would say maybe 15% of the time or 20% max, it’s just fungal overgrowth without SIBO, parasites or some other issue. 80% or 85% of the time, it’s something else in addition to fungal overgrowth. Great point, Steve.

Diet for Treating Yeast Overgrowth

Moving on to the second point, which is the appropriate diet for treating yeast overgrowth. Nada mentioned she’s been on GAPS for six months. This is certainly a good choice, with some caveats, for yeast overgrowth. Now, if you’re not familiar with GAPS, it’s based on a specific carbohydrate diet. Both of those approaches remove complex carbohydrates—polysaccharides and disaccharides—from the diet. So when we talk about carbohydrates, we’re talking about different arrangements of glucose molecules. We have monosaccharides, which are single sugars like glucose, which are very rapidly absorbed in the upper part of the small intestine. They just don’t require a lot of absorption, because single molecules can pass directly across the lumen of the gut into the bloodstream. Then you have things like disaccharides, which would be lactose, as an example, which have to be split. They’re double sugar molecules. They have to be split into single sugar molecules before they can be absorbed. In people with poor digestion and absorption, fungal overgrowth, SIBO, and these conditions, those disaccharides don’t get properly broken down. They linger around in the gut, and they can become food for pathogenic yeast, bacteria, and other critters in the gut that we don’t necessarily want to be feeding. Then polysaccharides would be starches or any carbohydrates that have longer chains of glucose molecules linked together. They’re even more difficult to break down. That’s the theory with Gut and Psychology Syndrome (GAPS) and Specific Carbohydrate Diet (SCD). So the idea is if you have a fungal overgrowth, you should avoid disaccharides and polysaccharides, because they’re difficult to break down and they may potentially feed these overgrowths or infections.

Now I want to point out that overgrowth is probably the best term, because Candida is a normal resident of the digestive tract, as are many other species of bacteria that become overgrown in SIBO. It’s not like you have an infection with a parasite or something that shouldn’t be in the gut but is there. What’s generally happening in these situations is if something that is normally in the gut has become overgrown and overrepresented in relation to some of the other beneficial species of gut bacteria. So the reason I mention that is because it hints at a different approach. The idea is not to just completely wipe out these species, because that’s not even necessarily desirable. The idea is to get things back into balance. That’s really the focus of any kind of treatment for fungal overgrowth.

Steve Wright: That’s such a great point, Chris, that I think has taken a long time to sort of begin to get out in the world. So a lot of the articles people are going to be reading when they have yeast overgrowth are not pointing that out. I think that’s one of those other fundamental beliefs, that if you have the belief that all yeast is bad or something like that, then you’re probably going to adopt a different treatment strategy that I think you and I have both seen to be very ineffective.

Chris Kresser: Yeah. Well, the systemic antifungal drugs are a good example of that. They can just really wipe out fungal species in the body. That can have a pretty dramatic effect. When you move from yeast overgrowth and you start using those drugs, you can have a big improvement in symptoms. But if you take them for too long, you start wiping out the beneficial yeast in the body. Beneficial yeast actually protect against bacterial overgrowth. So ironically, what happens with long-term use of those systemic antifungals is you can have a higher risk of SIBO, bacterial overgrowth, and dysbiosis that’s caused by a lack of beneficial yeast. You know, we need to get away from this warlike mentality that we have with—I mean, I think this came out of the whole age of antibiotics and the discovery that pathogens cause disease. That was an important discovery. But it led to this sort of warlike mentality where we’re going to use these powerful drugs to absolutely obliterate and destroy bacteria and other pathogens. But of course, now we have a much different understanding, where we know that these bacteria are—we live in symbiosis with them. We absolutely depend on them for not only our survival, but for several different aspects of health. So we’ve gotten a little bit overzealous in our killing mentality. I think in the next—it’s already shifting, as you said, Steve. Within the next 10 to 20 years, there’s going to be much more of an appreciation of balance and regulation of the ecosystem, rather than the carpet bombing type of approach we’ve been doing so far.

Back to the diet. The trouble with GAPS and SCD, depending on how they’re done, is that they can be extremely low-carb diets. If they’re extremely low-carb, they can become ketogenic, which means you start producing ketones. Paul Jaminet was one of the first people to start talking about this a few years ago. But there are several studies that suggest that Candida and other yeast can actually thrive on ketones. So this is one of my biggest problems with a very low-carbohydrate diet—GAPS, SCD or even sort of typical Candida diet—that removes every possible source of glucose or sugar in the diet. That can lead to ketone production. Then there are studies, for example, that show that neutrophils, which are white blood cells, are less able to kill Candida when ketones are present. There are studies of diabetic patients with ketoacidosis—you know, a lot of ketone production—developing Candida overgrowth. There are studies of obese people developing Candida infections when fasting causes ketosis. There are studies showing that serum drawn from fasting patients is less protected against Candida than serum drawn after meals, and that antifungal drugs, and I would assume botanicals, tend to work better in a fed state than a fasted state, where ketone production would be occurring. So there’s this whole kind of constellation of evidence that’s pointing to the idea that ketone production is not a good idea.

I guess what I would say is if you do do a GAPS or especially like a GAPS intro or an SCD intro, that should probably be temporary. Even then, you might not want to do it so that it’s so low carb. You can test your urine with Ketostix to make sure that you’re not in ketosis and you can eat more of the non-disaccharides—you know, the safe fruits, for example, that are permitted on the GAPS or the SCD diet, if you’re continuing to avoid the disaccharides and polysaccharides, like the starches and the more complex sugar molecules.

Steve Wright: I think it’s important to sort of point out what I think you’re hinting at, which is that these diets—GAPS and SCD, which I’m a big fan of and have done a lot of work around—are not the solution.

Chris Kresser: Yeah.

Steve Wright: It’s another form of sort of starving and destroying. A lot of people, including myself, have gotten a lot of benefit from being on a diet like this. But the idea that any one of these diets is going to starve or kill yeast infection or a SIBO infection is, in my opinion, thoroughly false now.

Chris Kresser: You’re a step ahead of me. That’s point number three that we’re about to make.

Steve Wright: Okay, cool.

Chris Kresser: Awesome. We’re on the same page. Before I go on, I do want to say that generally, in my practice, I don’t start people with GAPS or SCD for fungal overgrowth or SIBO. We use a low-FODMAP diet for those conditions. I find that that typically works very well. FODMAPs are a slightly different take. It’s a similar theory. The idea is FODMAPs are fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. So there are certain types of carbohydrates that are poorly broken down. They become food for the fungal overgrowth or bacterial overgrowth. However, with a low-FODMAP diet, I think it’s easier. There are more carbohydrates that are permitted, including some starches, which might seem contradictory to the GAPS approach. And it is. It’s a different approach. But I found that many people can tolerate some starches on the FODMAP diet if they have fungal overgrowth and bacterial overgrowth. They do well and we see success. You know, we test people and then we retest people after they’re treated. We see the fungal markers and the bacterial markers changing and going away. If they don’t, we might then switch to like a GAPS or SCD intro, as long as there are enough carbohydrates so that it’s not ketogenic. I think either of those will work. Low-FODMAP diet is a starting place. GAPS or SCD, as long as you’re eating enough fruit and carbohydrates, so that you’re not going into ketosis. And again, you can test that with the Ketostix, which are these urine strips. Those are both good choices.

Steve Wright: One thing that neither one of us have mentioned—probably because we don’t like it or don’t like to mention it—is the anti-Candida diet, which anybody who’s Googling this issue is going to run into a thousand websites that talk about this.

Chris Kresser: Yeah. I’m right there with you. I was just about to mention that I’m not a big fan of the anti-Candida diet. I think it’s both unnecessarily restrictive and not restrictive enough. In the unnecessarily restrictive category, it removes literally every source of glucose. I mean, on the extreme versions, you see even carrots and things like that prohibited because they have too much sugar. However, as I mentioned, if you do that, you’re going to probably end up in ketosis, which can actually make things worse. And I’ve just never seen any peer-reviewed evidence that suggests that that’s necessary. In terms of the not restrictive enough, many Candida diets actually permit grains, which is strange when they’re trying to get rid of every source of sugar. Grains are ultimately carbohydrate, for the most part. They’re also poorly broken down for many people because they’re complex carbohydrates. So you’ll see the anti-Candida diet permitting grains, particularly the alternative grains like quinoa, millet, and things like that. I just don’t see those things working well for most people who have gut issues. That’s something to keep in mind. I don’t think the anti-Candida diet is very effective. If it was, you wouldn’t see people on it for years and years having the experience that they have. So that’s something to be avoided.

When to Use Antimicrobials

Point number three is what you just mentioned a little while back, Steve. That’s this—diet is not typically enough to treat fungal overgrowth and SIBO, in my opinion. It’s definitely a big part of strategy and it’s important. But when we have a patient that has fungal overgrowth or SIBO, we absolutely, without exception, will use antimicrobials. We start with botanicals. 90% of the time, that’s what we use. In some cases where the patient has just recurring, recalcitrant infections, we might start to use some prokinetics like low-dose naltrexone and possibly rifaximin and neomycin, if they have a methane overgrowth, which are medications. But almost exclusively, we’re using botanical, nutrient-based protocols. Some of the ones that we use, that have research behind them, and tend to work well would be undecylenic acid; uva ursi; cat’s claw; pau d’arco; lauric acid, which is monolaurin (Lauricidin); high-dose biotin actually is antifungal, like 5 mg per day; Gymnema sylvestre, which is an herb that has been used historically in India for blood sugar issues because it reduces sugar cravings and helps balance blood sugar, has recently been shown to be very effective in terms of inhibiting Candida growth; Saccharomyces boulardii, which is a beneficial strain of yeast, has been shown to inhibit the growth of Candida and also reduce inflammatory cytokine production that is associated with cells that are infected with Candida; soil-based probiotics like Prescript-Assist are I think effective in terms of outcompeting Candida for adhesion sites in the gut.

So all of these things, many of which we’ve talked about before, can be really effective in an overall antifungal strategy. I think they’re very important. And if you’ve been doing a GAPS approach, for example, for six months, and you still have symptoms and you’re not doing these other things, then that’s absolutely something to look into.

Restoring and Rebuilding the Gut

The last point would be—remember the kind of two-phase approach, which is when there’s any kind of infection, the first phase is clearing out the infection and the pathogens or the overgrowth, if it’s not an infection but it’s an overgrowth. But the second phase is really important as well. That’s restoring and rebuilding. The reason you can’t necessarily do both at the same time is some of the things that you use to restore and rebuild, like prebiotics, for example, can actually make the overgrowth worse. So resistant starch and non-starch polysaccharides, which are FODMAPs, of course, and also prohibited on a GAPS type of approach, they’re really helpful over the long term for restoring, growing beneficial bacteria in the colon. The reason you want to do that is because that’s what’s going to prevent a recurrence of fungal overgrowth in the future.

What I often see happening is patients will focus too much on the killing part and the eradication. They’ll stay on that diet or that approach kind of perpetually. They’re essentially continuing to starve their good gut bacteria. It’s interesting to see that there have even been studies about this now. I recently saw a paper that essentially was saying, something that we could have talked about, Steve, on the show. But the paper was saying, “Yeah, the low-FODMAP diet is undoubtedly effective for IBS, but maybe we don’t want to be prescribing this to patients long term because it’s really low on microbiota-accessible carbohydrates, which are the types of carbohydrates that feed the beneficial gut bacteria.” Now, of course, we know how important that is over the long term. I thought it was a great paper, because the researchers were basically backing up what we’ve said numerous times on this program, which is you have to distinguish between a therapy, something that has a therapeutic effect and that you use for a short period of time until you don’t need it anymore, with something that you might do over the long term. To use an analogy, if you need a raft to cross the river, when you get to the other side of the river, you just leave the raft behind. You don’t carry it on your head—well, unless you’re doing some portage and you’re expecting another river pretty soon. But the basic idea is you use it when you need it, and then you leave it behind. For whatever reason, people have a really hard time grasping that. You see that in the low-carb world I think, where I think it can be a super effective therapy and a shorter-term approach for a lot of conditions and people, but doesn’t necessarily need to be the lifetime approach. Or the fact that it tends to work really well as a therapeutic intervention, that doesn’t necessarily translate into meaning that eating carbohydrates led to the condition in the first place. It all tends to get kind of convoluted.

The point here that I really want to stress is that once you get the Candida or fungal overgrowth back into balance, that’s not the stopping place. The next step from there is to rebuild then your beneficial gut bacteria, which is what will prevent the Candida from getting overgrown again. I can tell you, and I’m sure you’ve had this experience, Steve, that people who get Candida, they don’t often just deal with it once; it tends to recur and be an issue. I think one of the reasons for that is they don’t stress the rebuilding part as much as they should.

Steve Wright: All right. So I’m just going to recap this. Correct me if I’m missing any here, Chris. But working backwards, one that you just mentioned was people tend to stay in the killing phase too long and don’t think about actually rebalancing the microflora and actually feeding it. Some people assume that diet is the solution to yeast and fungal overgrowth, when many times, it’s not; there needs to be other interventions. When people do do diets to try to help with yeast overgrowth and Candida, they typically will end up on a ketogenic diet, which can actually inhibit sort of the short-term treatments that will actually get rid of the Candida. Then I think another big one that we mentioned was the idea that—I think you put around 80% to 85% of the time, it’s not just a yeast overgrowth issue.

I think this is one of the reasons why people keep getting yeast overgrowth as well. It’s because they don’t ever get off the killing protocol. They don’t realize that there’s an 80% chance or more that they have maybe another infection, they have a hormone issue or they have an autoimmune issue that they’re not looking at.

Chris Kresser: Yeah. Great recap, Steve. Perfect. Maybe we’ll call this episode, “Four Biggest Mistakes People Make When Treating Yeast Overgrowth.”

Steve Wright: Awesome.

Chris Kresser: I like it. All right, everybody. Thanks for listening again. Remember to submit your questions so your voice can be heard. Thanks, as always, for listening.

Steve Wright: In-between episodes, if you want to get Chris’s latest studies or the latest recipes he’s posting, things like that, make sure you’re following him on social media. If you’re a Facebook user, go to Facebook.com/ChrisKresserLAc. If you’re a Twitter user, go to Twitter.com/ChrisKresser. Thank you for listening. We’ll talk to you on the next show.

Chris Kresser: Thanks, everyone.