The bacteria in your digestive system have a huge impact on your overall health. Keep them balanced with these tips.
Deep in your digestive system, trillions of microbes are hard at work 24/7. They churn out beneficial compounds, help your body break down and absorb key nutrients, and protect you from invading germs.
“Your gut microbiome is like a super-computer, says Vincent M. Pedre, M.D., a board-certified internist in private practice in New York City and author of the book Happy Gut. “Gut bacteria play beneficial roles in blood sugar control, immunity, brain health and emotional well-being.”
There are thousands of types of microbes living in your large intestine. But you don’t have to rely on probiotic supplements to keep them healthy. Smart lifestyle choices can help nurture these good gut bugs, Dr. Pedre says. Eating a nutritious diet, exercising regularly, and lowering your stress levels can make a big difference.
And you don’t need expensive home microbiome tests to get a sense of how your inner “zoo” is doing.
“If your gut digests food easily and comfortably and your bowel movements are normal — no diarrhea or constipation on a regular basis — your microbiome is likely healthy,” Dr. Pedre says.
Here’s your guide to a healthy gut microbiome, plus the best ways to keep your “gut bugs” happy and balanced.
What is the role of a healthy gut microbiome?
Beneficial bacteria in your gut have plenty of jobs. They churn out helpful compounds such as short-chain fatty acids, which help control inflammation. And they regulate immune-system protectors like T cells, macrophages and natural killer cells.
A healthy microbiome protects the lining of your intestines. This helps keep harmful compounds out of your bloodstream.
Your gut also communicates with your brain through the vagus nerve. This connection helps manage digestion and immunity.
A 2019 Journal of Microbiology and Biotechnology study also suggests that having a wide variety of helpful bacteria in your gut could keep you healthier as you age and even promote longevity.
What are the barriers to a healthy gut microbiome?
Modern life isn’t kind to these little helpers. Your microbial balance can be thrown off by lifestyle habits such as:
A high-fat diet
Alcohol use
Lack of exercise
Not eating enough fiber
Tobacco use
What happens when your gut microbiome is out of balance?
When your gut microbiome is out of balance, you’re at greater risk for a wide range of chronic conditions, according to the American Gastroenterological Association.
In a 2019 review in the Journal of Experimental Medicine, researchers from the University of California, San Francisco, linked an unhealthy gut microbiome to health problems that affected the body from head to toe.
This includes:
Crohn’s disease
Depression
Diabetes
Eczema
Heart disease
Inflammatory bowel disease
Low bone density
Psoriatic arthritis
Stiff arteries
What role does exercise play in a healthy gut microbiome?
Regular exercisers have a greater diversity of helpful gut bacteria than their less active peers, according to an April 2019 review from the University of Illinois Urbana-Champagne.
Workouts help tame inflammation, the researchers explain. In turn, that helps nurture the inner lining of your large intestine, creating a healthy environment for good bugs to thrive.
Exercise may also help encourage the reproduction of good bacteria by raising your body temperature.
And like your SilverSneakers instructors, your gut bugs want you to stick with exercise: The study authors report that microbiome diversity drops when people give up frequent forms of physical activity.
Most healthy adults should aim for 150-minutes of moderate-intensity exercise plus two days of strength training each week, according to the current Physical Activity Guidelines for Americans.
What are some other ways to take care of your gut microbiome?
Just as certain lifestyle practices can throw your microbiome out of whack, healthy habits can help it flourish.
Tip #1: Eat a variety of fiber-rich foods.
Gut bugs like the indigestible fibers in fruit, vegetables, whole grains, beans and nuts, Dr. Pedre says.
The more variety, the better, he adds. That’s because a wider variety of fiber sources feed a wider variety of healthy gut bacteria.
As part of the University of California, San Diego’s American Gut Project, researchers examined the eating habits and stool samples of more than 11,000 people. The results? People who ate at least 30 types of produce in a week had a more diverse gut microbiome than those who ate 10 types or fewer per week.
Some ideas to increase your fiber intake:
Include two types of berries as part of your breakfast.
Add more than one vegetable to sandwiches and soups.
Eat a mixed salad every day.
Vary your grains — in addition to oatmeal and brown rice, try quinoa, bulghur, or farro, for example.
Tip #2: Add fermented foods slowly.
Fermented foods contain many good bacteria that help keep your gut microbiome happy naturally, according to the Cleveland Clinic.
“Having fermented foods like yogurt, kefir, sauerkraut or kimchi a few times a week is a great idea,” Dr. Pedre says.
In a 2021 Cell study, 36 women and men ate diets that included either high-fiber foods or fermented foods for 10 weeks. Researchers found that the fermented-foods group had greater gut-bug diversity and less inflammation than the high-fiber group.
“Fiber-rich foods are still very important for long-term gut health,” Dr. Pedre says. “But fermented foods had a surprisingly big effect in just a few weeks.”
Look for yogurt or kefir (a yogurt-like drink) that has live active cultures. You’ll see lactobacillus and Bifidobacterium on the label.
“Go for plain types instead of flavored, which have added sugar,” he says. “You can add your own fruit for natural flavor and some fiber.”
Also try kimchi (pickled cabbage), sauerkraut, tempeh (made with fermented soy), miso soup, vegetable brine drinks, or kombucha.
Add these items into your diet slowly, he adds. If you load up on fermented foods too quickly, you might have to deal with some uncomfortable side effects, like gas, bloating, and nausea.
“Start with a small amount at first, like a spoonful of sauerkraut juice or an ounce of kefir, to see how your body reacts,” Dr. Pedre says. “Then slowly increase.”
Tip #3: Cut back on added sugar, saturated fat and meat-heavy meals.
Foods that are high in added sugar and the saturated fat that is found in dairy, meat, eggs, and cheese can prompt the growth of harmful gut bacteria, Dr. Pedre says. So can skimping on produce and whole grains.
When participants in a small Harvard University study ate only animal-based foods (meat, eggs, cheese) for five days, their levels of a gut bacteria associated with inflammatory bowel disease went up.
The takeaway? Nothing beats a well-rounded diet.
Fill half your plate with fruits and veggies — go for lots of different colors
Fill one-quarter of your plate with grains — make half your grains whole grains
Fill one-quarter of your plate with protein — vary it from meal to meal and be sure to include some plant-based proteins
Tip #4: Ask your doctor about probiotic supplements.
In addition to probiotic foods, you can also ask your doctor if probiotic dietary supplements might be right for you. Probiotic supplements come in different forms, including capsules, powders, and liquids.
Research suggests that some types of probiotic supplements may help reduce risk for diarrhea if you’re taking antibiotics. They may help with symptoms of irritable bowel syndrome.
Unlike medications, dietary supplements aren’t regulated by the FDA. Always talk with your doctor before starting any supplement. This is especially important if you take medication regularly for a health condition, as some supplements interfere with medicines.