Gutmaxxing: Should you do it?

Author's Bio: Ashley Oswald, RDN, IFNCP, CLT, LD

Your gut contains trillions of microorganisms.

And according to the internet, apparently those microorganisms are now something you need to maxx.

Because we’ve had looksmaxxing, sleepmaxxing, proteinmaxxing, fibermaxxing…

And now, naturally, we have gutmaxxing.

https://youtu.be/RV3QHfzbUVg

[Video Transcript Below Video - it is the same information]

What Is Gutmaxxing?

The basic promise sounds incredible.

Improve your gut microbiome, and supposedly you could improve your digestion, your immune system, your mood, your energy, maybe even your skin.

So people are loading up on fermented foods, eating ridiculous amounts of fiber, taking probiotics and prebiotics, drinking kombucha, buying microbiome tests, tracking their poop...

Basically treating their intestines like a Formula One car that needs constant tuning.

But here’s what makes gutmaxxing interesting.

Unlike a lot of internet health trends…

there is actually some very good science hiding underneath it.

The problem is separating that science from the stuff that just gives you expensive diarrhea.

So what exactly is gutmaxxing?

Does it actually work?

And should you be doing it?

Because the answer is yes…

but probably not in the way TikTok wants you to.

What Are You Actually Trying to “Maxx”?

First, we need to understand what you’re actually trying to “maxx.”

Inside your digestive tract lives an enormous ecosystem of bacteria, viruses, fungi and other microorganisms collectively known as your gut microbiome.

And these things aren’t just freeloaders.

Your gut microbes interact with the food you eat, produce different metabolites, help break down compounds your body can’t digest on its own, and interact with your immune system.

So the basic idea behind improving your gut microbiome isn't crazy.

Where things immediately get messy is this phrase:

“a healthy microbiome.”

Because what exactly does that look like?

There isn't one universally perfect collection of bacteria that every human should have.

Your microbiome is affected by your diet, your environment, medications, your age, your lifestyle and probably a bunch of variables we still don't completely understand.

Which means when someone online tells you that they have discovered the perfect gut-health protocol for everyone…

that should immediately make you suspicious.

And this is the first rule of gutmaxxing:

Your microbiome is not Pokémon.

You don't need to collect every bacteria.

You also don't need to obsessively optimize a microbiome diversity score like it's your credit rating.

Gutmaxxing Rule #1: Eat Fiber

But there are some things we know pretty confidently are worth doing.

And number one is incredibly boring.

Eat fiber.

I know.

Revolutionary.

But fiber is one of those things where internet health culture accidentally rediscovered something nutrition scientists have been telling us for decades.

Fiber-rich foods include things like beans, lentils, vegetables, fruit, nuts and seeds.

And certain fibers make their way into your colon, where microbes can ferment them and produce compounds such as short-chain fatty acids.

Meanwhile, most people aren't exactly crushing their recommended fiber intake.

And when I say most people...

I mean most people.

More than 90 percent of women and roughly 97 percent of men in the United States don't consume the recommended amount of fiber.

Which is kind of amazing.

We've somehow created an entire wellness industry around optimizing obscure bacterial species…

while almost nobody is doing one of the most basic things we already know is good for the gut.

So how much fiber are we actually talking about?

For adults age 50 and younger, the traditional recommendation is around 25 grams per day for women and 38 grams per day for men.

After age 50, those targets are somewhat lower.

And if you have absolutely no idea how much fiber you're eating right now…

you're probably not alone.

For perspective, a cup of raspberries has around eight grams.

A cup of cooked lentils has around fifteen.

An apple has roughly four or five.

So this does not necessarily mean:

“Purchase a forty-seven-ingredient fiber powder manufactured in a laboratory.”

It mostly means:

eat more actual plants.

Does Plant Variety Matter?

But here's where gut health gets even more interesting.

It may not just be the amount of plant food you eat.

It may also be the variety.

One of the largest citizen-science microbiome projects, the American Gut Project, found that people who reported eating more than 30 different types of plants per week tended to have greater gut microbial diversity than people eating 10 or fewer.

Now...

before someone clips that sentence and creates the:

30-PLANT GUTMAXXING CHALLENGE

Thirty is not a magical number.

This was observational research.

It does not prove that eating your thirty-first plant on Sunday night suddenly unlocks an elite microbiome.

But I think the larger idea is useful.

Variety matters.

Instead of eating the exact same three vegetables every week, mix things up.

Beans.

Lentils.

Different fruits.

Different vegetables.

Whole grains.

Nuts.

Seeds.

Herbs and spices.

And once you start counting them, getting more variety is actually much easier than it sounds.

Don't Overdo the Fiber

But then we reach the part where the word maxxing becomes dangerous.

Because humans hear:

“Fiber is good.”

And somehow translate that into:

“Therefore I should consume an industrial quantity of chia seeds tomorrow morning.”

Please don't do that.

If you're currently eating ten or twelve grams of fiber a day and suddenly decide you're going to eat forty or fifty…

your microbiome might be thrilled.

The rest of your digestive system may file a formal complaint.

Increasing fiber too quickly can cause bloating, gas and cramping.

So the smarter approach is incredibly unexciting.

Increase it gradually.

Drink enough fluid.

And make changes you can actually maintain.

Maybe this week you add berries to breakfast.

Next week you add beans to a few meals.

Then you swap a refined grain for a whole grain.

Then some nuts or seeds.

And suddenly a few months later you're eating significantly more fiber and a much wider variety of plants…

without reorganizing your entire personality around bowel movements.

In other words, you don't need to fibermaxx.

You probably just need to fiberadequate.

Terrible hashtag.

Much better strategy.

Gutmaxxing Rule #2: Fermented Foods

But then we get to the second big part of gutmaxxing:

fermented foods.

Things like yogurt, kefir, kimchi, sauerkraut and other traditionally fermented foods have become almost synonymous with gut health.

And this is where things get genuinely interesting.

In a Stanford randomized study, researchers assigned healthy adults to either a high-fiber diet or a diet high in fermented foods.

The fermented-food group showed increased microbiome diversity and reductions in several markers of inflammation.

That's fascinating.

But notice what I did not say.

I did not say:

“KIMCHI CURES INFLAMMATION.”

It was a relatively small study.

And gut microbiome science is still an evolving field.

But it gives us a pretty good reason to think that regularly eating certain fermented foods could be one useful part of an overall healthy diet.

And in case you’re wondering how much fermented food they were actually eating...

it was a decent amount.

Participants gradually worked their way up to around six servings of fermented foods per day.

That included things like kimchi, sauerkraut and other fermented vegetables, vegetable brine drinks, kombucha, yogurt, kefir, and more.

And one serving wasn’t huge.

It was roughly a quarter cup of fermented vegetables, six ounces of yogurt or kefir, or six ounces of kombucha.

So this wasn’t just someone having yogurt with breakfast and calling it a day.

They were consistently eating fermented foods throughout the day.

What About Probiotics?

Now this is usually where gutmaxxing takes a turn.

Because why eat yogurt for a few dollars when someone can sell you a bottle containing...

EIGHTEEN BILLION SUPER MEGA ULTRA PROBIOTIC ORGANISMS.

And this brings us to probiotics.

Probiotics are live microorganisms that, when consumed in adequate amounts, can provide health benefits.

Sounds great.

Except there's one enormous detail people miss.

Probiotics are strain-specific.

Different microorganisms can have different effects.

So asking:

“Do probiotics work?”

is a little bit like asking:

“Does medicine work?”

Which medicine?

For what condition?

At what dose?

In whom?

Many probiotic products on the market haven't actually been studied for the exact health benefits they're marketed around.

And even products containing similar-looking organisms can have very different effects depending on the specific strain.

And despite the enormous probiotic industry, strong evidence for using them broadly to treat many digestive problems is surprisingly limited.

Even for conditions like IBS, major gastroenterology guidance has concluded that the evidence isn't currently strong enough to recommend probiotics broadly as a treatment.

That doesn't mean probiotics are useless.

Some specific strains have evidence for specific circumstances.

It means grabbing a random bottle because it has 50 BILLION CFUs written on the front is not necessarily sophisticated microbiome optimization.

Sometimes it's just expensive bacteria.

Should You Get a Microbiome Test?

And then we arrive at one of my favorite parts of modern wellness:

testing everything.

Because you can now mail your poop to a company and receive a beautiful dashboard showing you which organisms supposedly live inside your gut.

And I've got to admit...

that's cool.

I would absolutely want to look at it.

But there's an important difference between something being interesting…

and something being clinically useful.

And there's another problem with reducing your microbiome to a single score.

Your microbiome isn't static.

It changes.

Sometimes surprisingly quickly.

In one well-known controlled study published in Nature, researchers switched people onto dramatically different diets made predominantly from either plant or animal foods.

And measurable changes in the gut microbial community appeared within roughly a day of the new diet reaching the colon.

Even more interesting...

after the animal-based diet ended, the microbial community began moving back toward its previous structure within about two days.

Now, that does not mean eating a salad tonight completely rebuilds your microbiome by breakfast.

These were intentionally extreme dietary changes, and different parts of the microbiome can respond at different speeds.

But it demonstrates something important.

Your microbiome is dynamic.

Other research that has sampled people's stool every day for weeks has also shown that the abundance of many gut microbes naturally fluctuates from one day to another.

Which raises an interesting question about commercial microbiome testing.

If I mail off one stool sample on Tuesday...

what exactly am I measuring?

My lifelong microbiome?

My typical microbiome?

Or partly the microbiome influenced by what I've been eating over the last few days?

In fact, an international expert consensus on microbiome testing recommends that people not deliberately change their normal diet before providing a sample, because doing so could give a misleading picture of their usual microbiome.

So when a company gives you an incredibly precise-looking microbiome score from one sample...

that's worth remembering.

It may be useful information.

It may even be fascinating information.

But it's still a snapshot of a moving ecosystem.

And there's an even bigger issue.

A 2025 international consensus statement concluded that evidence supporting the clinical usefulness of many microbiome tests is still limited, and specifically discouraged consumers from ordering microbiome tests without a clinical recommendation.

Even more interesting, a National Institute of Standards and Technology evaluation of several commercial gut microbiome testing services found major discrepancies between providers.

Meaning you can send essentially the same poop to different companies...

and your results could be completely different.

So right now, I wouldn't treat one commercial microbiome score like your gut's final report card.

Do You Actually Need Gut Testing?

And in case you’re wondering, yes—we do still use stool testing in our clinic.

But we use it selectively, and only when we think it’s actually going to change what we do.

For most clients, we can make a significant improvement in their symptoms without ordering a long list of expensive lab tests.

Because more testing isn’t always better testing.

Sometimes the most useful approach is simply knowing when a test is actually necessary.

And this is really where working with an experienced clinician can make a difference.

Our clinicians have on average 7 years of schooling in nutrition science, with years to decades of experience helping clients with gut issues.

This is what our clients hire us for.

2 clients can come in with the same symptoms, but the plans that help them to get rid of those bothersome symptoms can be completely different.

This is also why we get clients who have spent hours on ChatGPT, but still schedule with us, to help them get clarity on what will actually work for THEM.

When Gutmaxxing Goes Too Far

And next we come to the biggest problem with gutmaxxing.

It turns healthy behaviors into optimization behaviors.

Those aren't always the same thing.

There is an enormous psychological difference between saying:

“I eat beans, vegetables, fruit and yogurt because they're good for me.”

and saying:

“I need to manipulate my Firmicutes-to-Bacteroidetes ratio before breakfast.”

One is a healthy habit.

The other sounds like you're preparing your colon for the Olympics.

And whenever optimization culture enters health, there's a predictable progression.

First:

“Eat more fiber.”

Then:

“Eat thirty different plants.”

Then:

“Take this probiotic.”

Then:

“You need prebiotics.”

Then:

“Actually you need postbiotics.”

Then:

“You need this $300 microbiome test.”

Then:

“Your test says your bacteria don't like tomatoes.”

And six months later you're standing in Whole Foods afraid of a blueberry.

That's the point where gut health stops making you healthier.

Because the goal shouldn't be to create the theoretically perfect microbiome.

The goal should be to create a diet and lifestyle you can actually sustain.

So, Should You Gutmaxx?

So...

should you gutmaxx?

Kind of.

But I would steal the useful behaviors and completely ignore the ideology.

If your version of gutmaxxing means:

Eating a greater variety of plants.

Getting enough fiber and increasing it gradually.

Eating fermented foods.

Getting adequate sleep.

Exercising.

Not smoking.

Avoiding unnecessary extreme diets.

And generally eating a varied, minimally processed diet...

great.

You have successfully gutmaxxed.

Except you'll notice something interesting.

Almost none of that requires a supplement subscription.

You don't need fifteen powders.

You don't need a poop dashboard.

You don't need to eliminate fourteen food groups because an influencer said they're “inflammatory.”

And you definitely don't need to spend every waking moment thinking about the bacterial demographics of your intestines.

When Gutmaxxing Could Make Your Symptoms Worse

Also, if you're dealing with excessive gas, bloating, abdominal pain, diarrhea, constipation, acid reflux, and/or other bothersome symptoms,

Then gutmaxxing could make your symptoms worse. Consider scheduling with our clinic to help get your gut into a better spot, so that you can tolerate an increase in fiber and fermented foods.

Because sometimes a gut problem is not a microbiome optimization problem.

The Bigger Lesson From Gutmaxxing

And I think this is the bigger lesson from gutmaxxing.

The microbiome is genuinely one of the most fascinating areas of human biology.

We're learning that the organisms living inside us interact with our bodies in ways we barely appreciated a few decades ago.

There will almost certainly be incredible microbiome-based therapies in the future.

But that doesn't mean every microbiome claim being made today is true.

Science being exciting is not the same thing as science being finished.

And whenever there's a gap between those two things...

someone will happily sell you something to fill it.

So yes.

Take care of your gut.

Feed it plants.

Give it fiber.

Maybe give it some fermented foods.

Move your body.

Sleep.

And then occasionally do something revolutionary:

stop thinking about your gut.

Because perhaps the healthiest form of gutmaxxing is building habits good enough that you don't need to spend your life optimizing them.

Learn How to Make Your Own Fermented Foods

And if you’re curious to learn how to make your own fermented foods, we do have 4 videos up on our channel: fermented salsa, kimchi, fermented carrots, and the most popular one being How To Make Fermented Lemons.

Check it out here https://youtu.be/Q8e55rrCT_w

And until next time, stay curious.

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