By now you know the drill at the doctor’s office: Stick out your tongue. Drop your drawers. Take a dump in a cup. . .er, what?
Okay, maybe you haven’t been asked for a stool sample yet.
But a good argument can be made for shipping some of your poo to a lab. Your feces can reveal a lot about your microbiome—the community of microbial organisms that lives on your skin and inside your nose, mouth, and especially gut.
You have 100 trillion of these critters, and an unhealthy biome can cause a range of problems from acne to anxiety, says George Weinstock, Ph.D., of the Jackson Laboratory for Genomic Medicine.
Don’t think of these microbes as freeloaders who move in and wreak havoc like a bad roommate.
They’re part of you. There are 10 of them for every one of your human cells, and together they make up the “superorganism” that is you, says Weinstock.
You pilot the ship, but your microbial friends—tiny warriors with names like Firmicutes and Bacteroidetes—man the turrets. They offer first-line defenses against pathogen invasions and signal your immune system when more antibodies are needed for backup.
“Every part of your body has a symbiotic relationship with your microorganisms,” Weinstock says.
Diversity is critical: Generally speaking, a wider range of microbes creates stronger protection from chronic health conditions and autoimmune diseases.
Depression, type 1 diabetes, obesity, even cancer—your risk of developing any of these maladies drops when your microbiome is as lush as a rain forest, he says.
To see how normal dudes fare, we created a contest: Two volunteers swabbed some used TP and sent the samples to a lab, uBiome (tests start at $89, ubiome.com), to learn whose gut was more diverse.
Volunteer one: Adam Smith, 24, with a history of acne and gastrointestinal problems. He controls both by avoiding grains, gluten, and sugar.
Volunteer two: Craig Merrick, 40, a gym owner who eats a healthy, well-rounded diet and works out hard four days a week. His biggest health threat is stress, which can cause inflammation and throw off gut bacteria.
About a month later, the results were in: Both guys had above-average biodiversity scores. But Smith had less biodiversity than Merrick—predictable, given Smith’s problems.
“If not for his diet changes,” which affect gut health, “his microbiome would probably have been much worse,” says Weinstock.
And both guys could still probably improve: A 2014 study in Proceedings of the National Academy of Sciences reports that the average microbiome of an American adult is about a third less diverse than those of our ancestors and people in less developed countries.
That may be partly due to our heavily processed diet and the overuse of antibiotics that wipe out good bacteria along with the bad.
There’s still a lot we don’t understand about the microbiome, says Weinstock. But we’re learning more all the time.
We already know several ways to improve its biodiversity. Hack yours with these tips and you’ll see an uptick in your immune function and overall health.
1. Eat Lots of Fiber
Gut bacteria love fiber: Researchers at NYU have linked an increased intake of fiber from beans, fruits, and vegetables with a greater abundance of both Actinobacteria (which produce natural antibiotics) and Clostridia, a class of microorganisms that’s been linked to decreased risk of colorectal cancer.
Related: 10 Weird Reasons You Can’t Poop
The average fiber intake in the study was 14 grams a day; you’d be wise to aim for almost three times that, which amounts to just under 3 cups of black beans.
2. Workout to Help Your Gut
You can bolster your biome at the gym. Male pro athletes have significantly more diverse gut bacteria and lower levels of inflammation than less active and sedentary men, a recent study in the journal Gut reports.
The researchers aren’t exactly sure how exercise diversifies a person’s microbiome, but the effect may be from a combination of breaking a sweat and eating for performance.
The athletes consumed 100 more grams of protein a day than the control group did.
3. Eat Whole Grains
The Paleo crowd talks about carbohydrates like they’re poison.
Pay no attention! In a recent study from the University of Nebraska, healthy adults who consumed 60 grams of whole grain cereal every day experienced significant improvements in metabolism, immune function, and microbial diversity.
Yes, fiber certainly played a role in those results, but the study authors suggest that whole grains might confer additional anti-inflammatory benefits.
4. Don’t Take Too Many Antibiotics
The current generation of prescription antibiotics are broad-spectrum—in other words, they target good and bad microbes indiscriminately.
Recent studies indicate that this can disrupt your microbiome within three days, and Swedish scientists say it can take up to four years to restore the balance.
No, you can’t always avoid antibiotics, but you can ask your doctor for the safest option.
For example, a Dutch study found that amoxicillin has no effect on microbial composition. (You shouldn’t pop the pills for these 5 Conditions You Shouldn’t Take Antibiotics For, either.)
5. Drinks Lots Of Coffee
Coffee’s laxative effect may signal that there’s something positive going on in your digestive tract.
Swiss scientists found that drinking three cups of java per day could bolster your gut’s levels of Bifidobacterium.
Related: Why Coffee Makes You Poop
They speculate that these beneficial microbes help prevent bad bacteria from moving in and taking up residency in your intestinal tract.
Credit probably goes to the slew of beneficial compounds that exist naturally in coffee, such as chlorogenic acids. So go grab another cup.