By Meghan Jardine, M.S., M.B.A., R.D., L.D., C.D.E.
Did you know we are only 10 percent human? Ninety percent of our cells are nonhuman, microbial cells. Since our diet influences our microbes, it’s true: We really are what we eat. The good news is that you can cultivate a new microbiota, formerly known as gut flora, in just 24 hours—by changing what you eat. Bacteria that live in our intestinal tract, also known as gut bugs, flourish off of colorful, plant-based foods. The latest studies on microbiota continue to show us how the process works, which explains why the mere mention of gut bacteria sparks conversations in both research labs and newsrooms.
Healthy gut bugs act like quarterbacks in our intestinal tracts: They call the shots and control the tempo by helping our bodies digest and absorb nutrients, synthesize certain vitamins, and rally against intruders, such as influenza and toxic cancer-forming carcinogens. In addition to boosting our immune system, microbiota sends messages to our brain and helps regulate metabolism. Over time, microbiota forms colonies to combat obesity, type 2 diabetes, heart disease, autoimmune disease, and even certain forms of cancer.
The bottom line: The more diversity you have in your gut bacteria, the better off you’ll fare in the long run.
Here are seven foods to help you get started:
1. Jerusalem artichokes
Benefits: High in inulin, strong prebiotic potential
Background: Inulin, an insoluble fiber, travels through our bodies from the small to large intestine, our colon. Once this insoluble fiber finds its way to the colon, it ferments into healthy micro flora. Other good sources of inulin include asparagus, leeks, onions, and bananas. Note: It’s good to ease into eating Jerusalem artichokes, as they may cause distress to people with sensitive digestive tracts.
Benefits: Restores health of the bacterial community, may reduce inflammation
Background: Like a peacemaker, bananas work to maintain harmony among microbes in the bacterial community, known as phyla. This is one reason bananas are a standard prescription for an upset stomach. Bananas may also reduce inflammation, due to high levels of potassium and magnesium.
Benefits: This high-fiber, corn-based grain has a fermentable component
Background: Corn, the base of polenta, earns credit for fostering a healthy gut. Polenta’s insoluble fiber travels directly to the colon, where it ferments into multiple strands of gut flora. It’s good to note that polenta, like kombucha, varies in fermentable components.
4. Broccoli and other cruciferous vegetables (kale, cabbage, and cauliflower)
Benefits: Cruciferous vegetables contain sulfur-containing metabolites, known as glucosinolates, which are broken down by microbes to release substances that reduce inflammation and reduce the risk of bladder, breast, colon, liver, lung, and stomach cancer.
Background: Like a game of Pac Man, glucosinolates latch onto carcinogenic intruders in our colon and kindly show these pathogens the way out. Over the long run, this pays big dividends: Studies show people who eat the most cruciferous vegetables reduce their risk of colorectal cancer by 18 percent. One more reason to load up on leafy greens!
Benefits: Can modify the microbiota to enhance immune function
Background: Our eyes are naturally drawn to anthocyanins, the pigment that gives blueberries a bold color, for good reason. We’re not sure if it’s the antioxidants, vitamin K compounds, or fiber that gives blueberries clout as a superfood, but we’re impressed with the results. Studies continue to show blueberries may help strengthen our memory, improve our immune system, and diversify our gut bacteria.
Benefits: Any legume will help release short-chain fatty acids (SCFA) that strengthen your intestine cells, improve absorption of micronutrients, and help with weight loss.
Background: Beans feed good gut bugs, which in turn revs up your immune system. Calorie for calorie, beans offer the most nutrition bang for your buck. They are packed with fiber, protein, folate, and B vitamins, which play a role in regulating a healthy gut and a healthy brain.
Bonus: Researchers from Toronto just published a study in the journal Obesity that finds beans (pulses) improve weight loss by enhancing satiety.
7. Fermented plant-based foods: sauerkraut, kimchi, tempeh, and soy sauce
Benefits: Fermented foods, such as beet radish kimchi or pickled ginger sauerkraut, are trending for a reason. They directly inoculate your gut with healthy live micro-organisms that will crowd out the unhealthy bacteria, improve the absorption of minerals, and improve overall health.
Background: Fermented plant-based foods are probiotics that have been found to improve the health of the intestinal cells, improve immune function, decrease allergies, reduce the risk of colon cancer, and treat diarrhea. You can make fermented foods at home and just as easily pick them up from a local grocery or health food store.
Meghan Jardine, M.S., M.B.A., R.D., L.D., C.D.E., is the associate director of diabetes nutrition education at the Physicians Committee for Responsible Medicine, a nonprofit organization dedicated to promoting effective medical practice, higher standards in research, and preventive nutrition.