The health of our microbiome—the trillions of microorganisms on our skin and in our gastrointestinal tract—is crucial to our own well-being. Recent research has shown a correlation between a flourishing community of healthy gut bacteria and the human host's good health, and vice versa. Most of us have already gotten this message—and food and supplement companies certainly have, judging by the scores of new products that advertise probiotic properties.
If you want to make a few easy changes to care for the healthy bacteria that share your body, it's important to separate the hype from the reality. First, what are we talking about here?
A probiotic contains a verifiable number of live bacteria, of a strain that has been shown to be beneficial to human health. Essentially, a probiotic adds to the community of good bacteria in your gastrointestinal tract.
A prebiotic is food for your bacteria—something you consume to help your bacteria grow and flourish.
Caring for your microbiome comes down to two basic principals: Expose yourself to plenty of good bacteria, and eat foods that help your bacteria thrive.
1. Eat plenty of vegetables, fruits, and whole grains. This is probably the most important thing you can do: Gut bacteria love fiber because it makes it to the intestine undigested where the bacteria can eat it up. They particularly like inulin, a kind of fiber found in artichokes, leeks, garlic, onion, Jerusalem artichokes, and asparagus.
2. Eat fermented foods—but not for the reason you think. Fermented foods like yogurt and kimchi are extremely healthful for both you and your microbiome, and they may even contain live, healthy bacteria, but scientists don't consider them true probiotics.
A probiotic, by definition, must contain a verifiably large number of live, beneficial bacteria. There are many things that can interfere with a fermented food's ability to provide a large number of live bacteria. Dragana Skokovic-Sunjic, a pharmacist and the author of Clinical Guide to Probiotics, says that some yogurt is heat-treated after culturing, which deactivates the bacteria. "They do not have much live bacteria left or the yogurt would be popping their lids," she says. "Yogurt is a great food, but you can’t rely on it to be a probiotic supplement."
Additionally, she says, some fermented foods have lots of live active bacteria early in the fermentation process, but as the fermentation goes on, they start to die off. She notes that if you open a jar of kimchi or sauerkraut and the jar pops and hisses, that's an indication that the bacteria are still alive and kicking. But exactly how many? It probably pales in comparison to the number in a supplement.
"Yogurt is a great food, but you can’t rely on it to be a probiotic supplement."
Daniel M. Neides, Vice Chair of the Wellness Institute at the Cleveland Clinic agrees. There are lots of foods that now claim to contain good bacteria—but they've got to make it to your plate alive. "When they add lactobacillus to foods my concern with that we don’t know how it was stored," Dr. Neides says. "It’s sitting in a warehouse over the summer, there is zero chance that that bacteria is still alive." He says that the only food he thinks of as a true probiotic is kimchi.
"But you can't eat it like ice cream," he says. "If you stick your spoon in the bottle and then in your mouth and then back in the bottle, you've now colonized the kimchi with the bacteria in your mouth, which will kill the bacteria you're looking for." The upshot is that fermented foods are undoubtedly good for you, but if you're looking for a surefire way to replenish your bacteria, food is an unreliable source.
3. Take a pharmaceutical-grade probiotic supplement. "I encourage patients to take a probiotic supplement. We lose good bacteria through attrition and you have to replenish," Dr. Neides says.
There's one big problem, though: In the United States, supplements are only very loosely regulated. A bottle might claim that each pill contains a certain number of live bacteria, but there's no regulatory body that's checking that claim. Not only that, but there's no way to tell if the company has stored the product correctly to ensure that the bacteria that were present at production are still alive when you take the pill.
"Those boxes of probiotics at CVS? You don’t know if they’re alive or not," Dr. Neides says. "So make sure that you find a good-quality pharmaceutical-grade product." Some of the best-quality probiotics voluntarily submit their products for independent testing, which provides reassurance that you're getting what you're paying for. Dr. Neides suggests asking your doctor for an independently tested recommendation or going to the Cleveland Clinic Wellness Institute's online store, where they sell Ortho Biotic probiotics. Dr. Neides himself takes a high-potency VSL 3 probioics. He says that the average person should aim to ingest a supplement of 20 billion CFU (colony forming units) per day. But there is no way to overdose on good bacteria, and he actually takes much more than that himself.
Why doesn't he suggest everyone take as high a dose as he does? Basically, cost. If you're healthy, there's no proven need for you to shell out for the high-potency supplements. Another useful resource for finding a high-quality probiotic is Skokovic-Sunjic's Clinical Guide to Probiotics, which is also available as an app. It only includes probiotic supplements that contain strains of bacteria that have been scientifically proven to have certain health benefits.
4. Limit sugar and refined carbs. "Diets rich in processed carbohydrates, refined starch, sugar, bad fats are some examples of bad food that has tendency to disrupt microbial balance in our gut," Skokovic-Sunjic says.
5. Use regular soap instead of antibacterial. In most home settings, antibacterial soap just isn't necessary. Warm water and mild soap will do the job.
6. Garden. Exposing yourself to the microorganisms in soil can add to your own healthy bacteria.