How To Feed Your Microbiome (And Why You Should)

Trillions of microorganisms, thousands of species — bacteria, fungi, parasites — all coexisting peacefully within us: This is your microbiome, which plays a critical role in your health.

From digestion to stimulating the immune system to breaking down toxins, your microbiome performs best if you take care of it. But do you know how to do that? And what are the consequences of an unhealthy microbiome?

So What’s a Microbiome?

Microbiome is the term for all of the microorganisms living primarily in our gut but also throughout the body — skin, reproductive organs, nose, lungs, mouth and saliva, eyes and even glands. Taken together, they keep our systems operating smoothly.

Different types of microbiota — the microscopic organisms in a particular environment — are found in different parts of our bodies. They also vary from person to person, and we don’t yet know all of the roles they play.

The largest concentration is in the colon, where they help synthesize vitamins and break down or ferment food. Why does fermentation matter? The microorganisms contributing to that process create beneficial enzymes, vitamins and fatty acids. What defines a healthy microbiome is unique to each individual, but a good balance is one in which pathogenic, or “bad,” microbiota coexist without inflammation or other problems with symbiotic, or “good,” organisms.

A disturbance in that balance can cause problems from gas to bloating to serious GI infections. Even too much “good” biota overgrowing where it should not be can cause problems — balance is key.

Caring for Your Microbiome

The composition of your microbiome is partially determined by your DNA, but research suggests that environmental effects start pretty much the minute we exit the womb. Are you in a high-stress career? A smoker? A frequent user of antibiotics? All of these things — and especially your dietary choices — affect your microbiome.

One of the most important nutrients when it comes to the microbiome is fiber, something most Americans don’t get enough of. Microbiota in the colon break down fiber to produce energy for the colon’s cell lining. If not properly nourished, these microbiota can begin to feed on that protective lining, putting you at greater risk from undesirable microorganisms.

Avoiding the overuse of antibiotics also is key — studies have shown them to be particularly disruptive to the balance of your biota. Consuming probiotics — foods that nourish your biota — when you are prescribed antibiotics can help maintain that balance.

Preserving and encouraging “good” gut bacteria has been associated with improved blood sugar levels, lower cholesterol, reduced bowel inflammation and better moods. Researchers are investigating the gut’s link to everything from colon cancer to Alzheimer's risk.

Probiotics and Prebiotics

Probiotics are foods, often fermented, that contain living cultures of good bacteria that help keep you healthy. Examples to add to your diet include:

• Kefir, a fermented milk drink
• Kimchi and sauerkraut, made from cabbage
• Yogurt
• Kombucha, a slightly fizzy sweetened tea drink
• Pickled vegetables
• Miso and tempeh, made from soybeans
• Some cheeses, such as mozzarella, cheddar, gouda and cottage cheese

Prebiotics feed the cultures in probiotics — think of them as the manure that enriches the garden of your microbiota. Examples include:

• Vegetables including garlic, onions, artichokes and broccoli
• Fruits including bananas and apples
• Nuts, such as almonds
• Whole grains, such as flax seeds, oats and barley

While it’s best to get these nutrients from solid food — so you get the benefit of their fiber, too — liquids like kombucha, apple cider vinegar or a kefir yogurt drink can be easier to tolerate. Any increase in fiber should be gradual — otherwise you might experience bloating, flatulence or loose stools.

If you have a hard time with fiber, probiotics can be taken via supplements. But be cautious: There are many brands, and not all offer the same benefits. It’s important to talk with your doctor or dietitian — especially if you are managing any medical conditions — to make sure you are taking a type and concentration that will benefit you.

Like all supplements, probiotics are not regulated by the FDA to the same standards as medication. There’s no guarantee that the probiotics in a particular supplement are alive and active — your healthcare team can steer you toward well-studied brands that have been proven effective and safe.

What You Can Do

When it comes to managing your microbiota, diet is one of the factors mostly under your control — along with not smoking, getting enough sleep, reducing alcohol consumption and doing your best to limit stress. Shoot for a diet rich in a variety of fruits, vegetables and whole grains — whole foods with dietary fiber. If you have medical constraints on your intake, a dietitian can tailor a plan that works for you.