Your mom was more right than she knew when she told you 'You are what you eat.'
Your mom was more right than she knew when she told you 'You are what you eat.' (iStock)

How to Boost Your Microbiome

Wondering how to ensure that your gut is healthy? We're here to answer your most pressing questions.

Your mom was more right than she knew when she told you 'You are what you eat.'

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.

Scientists are discovering that the microbes living in your digestive system may hold the secrets to improving performance, which is why scientists are investigating just what’s inside athletes’ guts. Want to improve your own microbiotic health? Here’s how.

So I Just Take Probiotics, Right?

Er, sort of. For more than a century, scientists have been looking for a probiotic-enhanced substance—something like yogurt, kefir, or kimchi that introduces new, live bacteria into your body—to cure what ails us. In the early 1900s, Russian immunologist Élie Metchnikoff sang the praises of Lactobacillus bulgaricus, a bacteria that gives yogurt its taste, claiming that it could ward off senility. (It can’t.) Today scientists know that probiotics can indeed solve a few problems. Got diarrhea or an upset stomach from a course of antibiotics? Eat some yogurt that contains live cultures (or some unpasteurized fermented pickles or sauerkraut) for a little relief. Promising clinical trials also suggest that one day soon, probiotics may be prescribed to treat irritable bowel syndrome or even depression.

Does Your Gut Hold the Secret to Performance?

“I’ll be the first to admit I eat a decent amount of ice cream,” says obstacle-course racer Amelia Boone. “Definitely more than I should.” New science is set to revolutionize the way we eat, train, and live.

Read More

But probiotics aren’t a panacea—and they can’t prevent you from getting sick in the first place. “The industry is predicated on maintaining wellness,” says Jack Gilbert, of the University of Chicago, “but currently there’s no evidence that long-term, continued consumption of probiotics maintains wellness.” The main bacteria in probiotics, Lactobacillus and Bifidobacterium, do aid with GI issues and reduce diarrhea, but there’s mixed evidence of how effective they are in probiotic form.

The High Performance Secrets Inside Athletes' Guts

Alex Honnold’s gut has way more Prevotella than the average American’s. In the name of citizen science, we peered inside the bellies of Outside staff—and seven elite athletes.

Read More

The science is still young, so for now researchers suggest supplementing probi­otics with prebiotics, which feed the bacteria already in your body. You can buy prebiotic powders, but the best way to get them is with high-fiber foods such as beans and veggies. Your gut bugs break down the fiber into helpful things like anti-inflammatory short-chain fatty acids. At the end of the day, scientists say, the best way to maintain a healthy gut is to—no surprise here—eat a varied diet filled with veggies, legumes, and fermented foods to get both pre- and probiotics. (Take a look at “3 Recipes to Boost Your Microbiome” for a few ideas.)

Should I Get My Biome Tested?

3 Recipes to Boost Your Microbiome

Sustaining the healthy bacteria in your gut requires fiber. The ideal healthy-gut diet for performance.

Read More

Roughly half a dozen companies will analyze your microbiome for you, identifying which bacteria dominate your gut and comparing your results with other people’s. Some will also provide everything from tailored dietary advice to customized probiotic ­regimens. The largest company, ­uBiome, offers physician-ordered tests that it claims can iden­tify pathogens associated with some diseases. But a microbiome test alone, says Rob Knight, head of the American Gut Project, can’t diagnose anything. Still, knowing if your gut is dominated by, say, bugs in the Firmicutes phylum rather than Bacteroidetes—which are associated with a leaner body profile—can help spur dietary changes. Maybe consider laying off the hamburgers and eating some plants instead. If you do want to use your results as a diagnostic tool, bring them to your doctor to rule out any egregious quantities of pathogenic bacteria.