Is "Fiber-Maxxing" Ruining Your Gut?

June 18, 2026

In this episode of the Health Optimization Medicine Podcast, Dr. Scott Sherr, Dr. Ted Achacoso, Dr. Jup Kuipers, and Dr. Allen Bookatz explore:

How did fiber become the latest health trend, and why might "fiber maxing" create problems for some people?
Why does the optimal amount of fiber depend on the health and composition of your gut microbiome?
What role do soluble fiber, insoluble fiber, and short-chain fatty acids like butyrate play in digestive health and longevity?
How can excessive fiber intake contribute to bloating, mineral depletion, hormonal disruption, and digestive discomfort?
Why is testing the gut microbiome often more valuable than blindly following nutrition trends or generalized dietary advice?

What We Discuss:

00:00 - Introduction: The Mainstream Fiber Trend
00:43 - Soluble vs. Insoluble Frameworks
01:57 - The Downside of SIBO & Fiber Overgrowth
03:38 - Chronic Bloating & Coining "Fiber Myalgia"
04:56 - SCFA Powerhouses: Propionate, Acetate, and Butyrate
06:16 - Epigenetic Signaling and Colon Cancer Prevention
07:14 - The Hormone Connection: Fiber Overdose & Amenorrhea
08:33 - The Mineral Heist: How Fiber Binds Essential Nutrients
09:16 - Caloric Displacement and Starving Your Mitochondria
10:28 - Final Takeaways: Gut Balance & The Rainforest Analogy

Full Transcript:


[00:00:00] Dr. Scott Sherr: Welcome back everybody to another episode of the Health Optimization Medicine podcast. We have our faculty here today. Dr. Yap, Dr. Ted, Dr. Allen, this is Dr. Scott. Today we are going to talk about fiber. Fiber minimizing, fiber maximizing... "fiber maxing" is the trend.

[00:00:14] Dr. Scott Sherr: Dr. Ted, you know a lot about fiber. In fact, I think you've called it the fourth macronutrient, right? We have proteins, carbohydrates, fat, and then fiber. Talk to us about fiber as you see it.

[00:00:43] Dr. Ted Achacoso: Fiber is actually a class of carbohydrates, right? And there are two forms of fiber: soluble fiber, that which actually breaks down into your calories, and there is insoluble fiber, those that add bulk to your stool. They both have their place in the human diet. You're supposed to consume about 34 grams of fiber a day. Most people don't look at the dietary component of the things that they buy.

[00:01:17] Dr. Ted Achacoso: I was there at the initial generation of high-fiber bars when they tasted like cardboard. And then now, they actually have almost perfected the flavor. They're palatable, but the thing is, you actually are required to drink a lot of water with them, which people don't do, right? Remember there is a concept of net carbs. Net carbs would be the total carbohydrate intake minus your insoluble fiber.

[00:01:57] Dr. Ted Achacoso: In my practice where I lecture doctors, they don't even realize that fiber is a form of carbohydrate, and second, they don't even know what net carbs are. That's a shame for medical education because we only have what, six hours of nutrition, which sucks, literally.

[00:02:10] Dr. Scott Sherr: So yeah. You've heard of this concept called fiber maxing before?

[00:02:26] Dr. Jup Kuipers: I have, but can you explain to me exactly how that works?

[00:02:31] Dr. Scott Sherr: So there's this trend out now where Ted mentioned about 34, 35 grams of fiber a day is what's recommended. But there's a trend on trying to maximize the amount of fiber you have on a daily basis. So you have your psyllium husk, you have your acacia powder, you have your green drinks. Piling it on to a place where, hypothetically, you're going to feel better. But can you see a problem with this potentially?

[00:03:02] Dr. Jup Kuipers: Are people reporting feeling better with this? I can definitely imagine this being a problem. I also work in family medicine and a lot of people come to me with gut problems—gas, bloating, whatnot—and our current healthcare system doesn't really have answers. IBS is a bucket term, a diagnosis of exclusion. They deal with a lot of testing, maybe even a colonoscopy, and they find nothing.

[00:03:31] Dr. Jup Kuipers: But what they fail to realize is that we can now actually measure your gut microbiome and see exactly the bacterial constitution of that microbiome. Now, if people have too few microbes in their gut, giving a little extra fiber is good; it feeds the bacteria. But if people have bacterial overgrowth or short intestinal overgrowth, and you give even more fiber, you just pile on the problems. So I can imagine people doing this trend to be very gaseous, bloated, and flatulating.

[00:04:16] Dr. Scott Sherr: So don't just "fiber max," I would say. What I'm hearing is the take-home point, Dr. Yap, is if you are already experiencing bloating, dyspepsia, fullness, discomfort after eating... perhaps fiber maxing is not the right course of action for you, and that might be an indication to see your friendly neighborhood health optimization medicine practitioner. I would say let's do fiber optimizing.

[00:04:39] Dr. Jup Kuipers: Fiber optimizing. Tell us what that looks like. Well, if you measure exactly what your gut microbiome looks like, you can see if what you eat can actually be digested and absorbed. Is there maybe too much bacteria? Is there bacterial overgrowth? Are there certain pathogenic bacteria there, or certain commensal strains that are good for you but are actually in too high quantities? And then you can decide, do I need more fiber, do I need less fiber, or do I need probiotics? Many people just pound probiotics not even knowing if they need it, or if they have leaky gut, and this can actually add to immune stress in your gut lining. So we can now measure these things, guys. Do it.

[00:05:34] Dr. Ted Achacoso: Yeah, my first exposure to fiber maxing—that was not the term then, we just used too much fiber—was with a non-athlete who took over 60 grams of fiber a day, and she basically stopped menstruating. If you look at it from the get-go, it's like there's no correlation, but there is. Estrogen has an enterohepatic circulation, meaning it goes out of the bile to get reabsorbed. So when you have too much fiber in there, it will adhere to your fiber and it will drop the estrogen levels, and your patient will stop menses.

[00:06:08] Dr. Ted Achacoso: And this is actually also true for female athletes who like to be lean, right? And they up their fiber intake, and aside from the fact that their testosterone levels also rise as female athletes, you know, they also tend to fiber max and then drop their estrogen, and their menses stop. Now, to come to the gist of fiber maxing really, the first effect that you will have, of course, is what? Bowel obstruction, right? Because you can't poop anymore.

[00:06:29] Dr. Ted Achacoso: The second one is that they do tend to bind minerals—called the mineral heist, the great big mineral heist of that. And then, we shouldn't forget also that too much fiber will cause fermentation, right? And then, the last big thing is the caloric displacement, right? Instead of filling your stomach with something that has nutritious carbohydrates, proteins, fats that are needed by your body, you starve your mitochondria by not providing them food. So you're lower in energy.

[00:06:50] Dr. Ted Achacoso: And that's what's called caloric displacement, right? So it's very really very simple: keep your fiber intake to 30 to 40 grams a day, stop relying on those bars for your fiber, and hydrate relentlessly. It's very important that if you have a high-fiber diet, you have to drink a lot of water.

[00:07:36] Dr. Jup Kuipers: What would be the optimal forms of fiber for a healthy diet in your opinion?

[00:08:02] Dr. Ted Achacoso: Personally, my favorite forms of fiber are green leafy vegetables, right? Others will prefer other vegetables, but I like leaves. I'm more of a rabbit, I guess.

[00:08:22] Dr. Scott Sherr: One thing I think is important too, as we talk about fiber, like why it's important, right? Is that fiber is the food that the bacteria in our gut to feed on, to break down, and to create what are called short-chain fatty acids, right? And you can measure these in stool looking at—there's three: there's propionate, acetate, and butyrate.

[00:08:30] Dr. Scott Sherr: Butyrate is the one that's probably the most important because butyrate is the one that is known to be an epigenetic signaler, so it helps with modulating your DNA in various ways to make you healthier over time.

[00:08:55] Dr. Ted Achacoso: And that it has already been studied that low butyrate levels are correlated with colon cancer.

[00:09:13] Dr. Scott Sherr: Right. And then there was an article a number of years ago called "Super Poopers," and people that live longer have more butyrate in their stool.

[00:09:26] Dr. Jup Kuipers: I actually just had a client who had severe bowel issues for years, and he had the lowest butyrate I've ever tested in a gut test, and supplementing it gave him relief in weeks. Just a night and day difference.

[00:09:54] Dr. Scott Sherr: Well, why is that right? Because butyrate is the primary fuel of the large intestine. So if you don't have the fuel powering the cells of your large intestine, you're not going to do very well, right? And then glutamine, of course, is the primary fuel of the small intestine too, so you have to think about these things. When you're trying to repair somebody's gut, you have to think about the fuels that run the gut, run the system itself. And the fuel for the heart is... fatty acids. It's love, though. Love is always the answer. To the cardiologists out there, it's not glucose, it's fatty acids, guys.

[00:10:32] Dr. Scott Sherr: So I think when we think about the gut, we think about it as an immune system too, right? That's another big piece of it. How much of the immune system is in the gut? I think it's around 80% or so, right? Yeah, it's mediated by the GALT—gut-associated lymphoid tissue, right?

[00:10:51] Dr. Ted Achacoso: I like to say this: when we were in med school, the largest immune organ was the bone marrow, right? And then 15 years ago, they changed it—the largest immune system is now the gut. And we didn't learn anything about it. The gut was something that you killed with antibiotics in medical school. When you gave people C. diff, thankfully that's changed a lot, and we know that there's a lot there.

[00:11:27] Dr. Scott Sherr: No, you're right. And then yeah, we gave them C. diff, and then we never taught them how to replete their healthy commensal flora, and then they hear about fiber maxing, and then they eat a bunch of fiber and they feel achy and unwell. Perhaps is there a new condition maybe we need to coin? "Fiber myalgia" from fiber maxing, perhaps? You heard it here first.

[00:11:51] Dr. Scott Sherr: Fiber myalgia. All right, we'll give you that one, that's funny. And so the key really is that we can test for all this, and I think that's what we do at Health Optimization Medicine. We look at the gut looking at maldigestion, look at dysbiosis, looking at metabolic imbalance, inflammation, infection. You can look at all these aspects of it and go, okay, this is what's actually happening. Then you can have an intentional way of actually optimizing it. But at least from my experience, it's not like it's an immediate process for people, it can take time. And sometimes, even ramping down the fiber in the beginning can be helpful as you're looking to optimize the system.

[00:12:31] Dr. Ted Achacoso: What is necessary is the concept in health optimization medicine is always about balance, right? Remember that we're not just balancing a single ecosystem here, these are sub-ecosystems within your gut, you know. They are of different species, they feed on different parts of your food separately, so they grow or contract according to what you feed them.

[00:13:27] Dr. Jup Kuipers: I always like your rainforest analogy about the gut, how how different populations like have their real estate in the forest.

[00:13:40] Dr. Ted Achacoso: Yeah, they have their niches, right? And and so they have their hunting grounds and so on, just like any other regular ecosystem. And that's why it's true, you are what you eat. Well, I think we can wrap it up. Thank you all for listening to another episode of the Health Optimization Medicine podcast. We coined a new term, thank you Allen, fiber myalgia. Fiber maxing, I think it's just been misplaced in my estimation. Thank you all for listening and we'll see you guys next time. Take care.