The Probiotic Boom Left Fiber Behind

Walk through a grocery store today and you’ll find probiotics everywhere.

Capsules.

Yogurts.

Drinks.

Bars.

Even foods that seem to be borrowing the language of the supplement industry.

It’s easy to come away with the impression that improving your gut health might be as simple as taking a probiotic every morning.

But there’s another part of the story that gets considerably less attention.

Your gut microbes need food, too.

And one of their favorite foods is fiber.

We already have a huge community living inside us

Your digestive tract is home to an enormous community of microorganisms collectively known as the gut microbiome.

They’re not simply passive passengers.

Gut microbes interact with the food you eat and produce compounds that can affect the environment in your digestive tract and potentially influence other aspects of health.

Scientists are still figuring out exactly how all of this works.

But one thing has become increasingly clear:

Diet matters.

Research has shown that dietary fiber can change the composition and activity of the gut microbiome. Different types of fiber can affect different microbes and produce different effects.

That’s important because fiber isn’t just something that helps keep you regular.

It’s also a source of nourishment for many of the microorganisms living in your colon.

So where do probiotics fit in?

Probiotics are live microorganisms that provide a health benefit when consumed in sufficient amounts.

That definition contains an important detail.

A probiotic isn’t simply “a good bacteria.”

Benefits are generally tied to a particular microorganism—and often a particular strain—that has been studied for a particular purpose.

The NIH points out that researchers still don’t know which probiotics are useful for many conditions, who is most likely to benefit, or what dose is appropriate in many situations.

So the idea that one daily capsule can broadly “fix” your gut microbiome is considerably more complicated than the advertising might suggest.

Here’s the part that’s easy to overlook

Imagine planting a garden.

You could add some new plants.

But if the soil isn’t providing what those plants need, simply adding more plants doesn’t necessarily solve the problem.

Your gut isn’t a garden, of course.

But the analogy makes an important point.

Adding microbes and nourishing microbes are two different things.

Prebiotics are substances that aren’t digested by us but can be used by particular microorganisms in the gut. Many types of dietary fiber can serve this role.

And that means the food on your plate may matter at least as much as what’s inside the supplement bottle.

We aren’t exactly drowning in fiber

Here’s another surprising part.

NIH research notes that only a small fraction of Americans consume the recommended amount of fiber.

Fiber comes naturally from foods such as:

• Beans and lentils
• Vegetables
• Fruits
• Whole grains
• Nuts and seeds

And you don’t necessarily need some exotic “superfood” to get it.

A bowl of beans, vegetables with dinner, berries with breakfast, or a handful of nuts can all contribute.

But don’t throw away your probiotics just yet

This isn’t an argument that probiotics don’t work.

Some specific probiotics have been studied for specific health problems, and research has found benefits in certain situations—for example, some strains may help with antibiotic-associated diarrhea.

The important distinction is between:

“This particular probiotic has evidence for this particular purpose.”

and

“Taking a probiotic is good for my gut.”

Those aren’t the same claim.

And even the UC Davis research emphasizes how much we still have to learn about the relationship between food, microbes and health.

The simpler question

Perhaps the most interesting question isn’t:

“Which probiotic should I buy?”

It might be:

“Am I giving my existing gut microbes enough of the foods they need?”

That doesn’t require an expensive supplement.

It starts with what you put on your plate.

And there’s something wonderfully unglamorous about that.

While the health industry keeps inventing new ways to sell us “gut health,” one of the most important things our microbes may need is something humans have been eating for thousands of years:

plants.

The takeaway

Probiotics aren’t necessarily a waste of money.

But they’re not a magic shortcut to a healthy microbiome either.

Before thinking about adding more bacteria to your gut, it may be worth thinking about something more basic:

Are you feeding the bacteria already there?

For many people, that means paying more attention to fiber-rich plant foods and less attention to finding a miracle capsule.