1. It Acts Like a Second Brain

There’s a reason your stomach feels like it’s tingling when you’re nervous or anxious. The enteric nervous system—a complex and sophisticated network containing over 100 million nerve endings—lines your gastrointestinal tract. It connects your gut and brain. “Many studies have linked changes in your microbiome to mood disorders like depression and anxiety,” says Pankaj Jay Pasricha, director of research at Johns Hopkins’s Division of Gastroenterology & Hepatology in Baltimore, Maryland. Some research has even found that eating probiotics could work similarly to antidepressants in easing the symptoms of depression and anxiety.

2. Your Gut Can Help Keep Your Skin Clear

A healthy microbiome can help to regulate the bacteria in other parts of your body, like your skin. According to Joshua Zeichner, M.D., a dermatologist with Mount Sinai Hospital in New York City, an unbalanced gut microbiome can cause inflammation that affects the entire body, including your skin, which can lead to breakouts. One study found that 54 percent of patients with acne had impaired microbiomes compared to those of the average person. You can also find skin-care products that contain probiotic extracts and prebiotics that can help with skin conditions like eczema or acne. Probiotics versus Prebiotics: Probiotics are live, active cultures (the good bacteria itself) that are thought to have health benefits and can help improve your body’s good bacteria. Prebiotics are nondigestible substances (such as nonsoluble fiber) that promote healthful bacteria growth. They also serve as food for probiotics, so consuming the two together can make them extra effective.

3. It Can Help Strengthen Your Immune System

A big portion of your immune system is actually based in your gut. “Your immune system depends on the microbiome to function properly,” says Janelle Ayres, Ph.D., professor at the Salk Institute for Biological Studies in La Jolla, California. “Some microbes in the gut help control how immune cells function; if the microbiome isn’t healthy, the immune system may become too active,” says Sarkis K. Mazmanian, Ph.D., Luis B. and Nelly Soux professor of microbiology at the California Institute of Technology in Pasadena. That’s one reason you should include fiber in your prebiotics; some of the by-products of fiber being broken down signal the immune system to stay calm.

4. Your Gut Can Help You Maintain a Healthy Weight

We all know that what you eat can have an impact on your weight, but there’s more to it than that. “A number of studies have shown there is a difference in the microbiome of people who are obese compared to those who are lean,” Mazmanian says. One reason is that the bacteria in your gut help break down fat, extract calories from food, and impact the production of appetite-regulating hormones like leptin and ghrelin. If there isn’t a balance between good and bad bacteria, your digestive system might not perform those functions as well as it could.

5. Your Digestive System Might Play a Role in Arthritis

This is related to how your microbiome plays a role in regulating your immune system. According to Mazmanian, an overactive immune system can lead to autoimmune conditions like rheumatoid arthritis. So far, research has found that an overgrowth of certain types of bacteria can trigger an inflammatory response that targets the joints. Microbes in your gut can even impact treatments and make certain arthritis drugs more or less effective. Research is still exploring the connection between probiotics and joint health, including whether the bacteria in yogurt can help reduce joint inflammation. Some early results have shown that probiotics might be even more effective than taking nonsteroidal anti-inflammatory medicines like ibuprofen.

Foods to Eat for Better Gut Health

One of the best ways to keep your gut healthy and encourage the growth of good microbes is to follow a plant-based diet high in fiber and low in fat, sugar, and processed foods. It might also help to add more of these prebiotic and probiotic foods to your diet: Prebiotics: apples, artichokes, asparagus, bananas, barley, beans, broccoli, cabbage, cacao, flaxseed, garlic, leeks, lentils, oats, onions, raw honey, and whole wheat. Probiotics: kefir (milk- or water-based), kimchi, kombucha (learn how to make kombucha at home), miso, pickles, raw/unfiltered apple cider vinegar, sauerkraut, tempeh, and yogurt (dairy or nondairy).

Should I Use Probiotic Supplements?

Even though some new research shows that the available probiotic supplements don’t impact the gut microbiome, some experts still admit to taking them. If you’re interested in trying probiotic supplements, follow these best practices:

A mix of probiotic strains is best, but certain strains can also help with specific issues. You can talk to your doctor to learn more about what might work best for you, or check out the American College of Gastroenterology’s overview of using probiotics to treat adult gastrointestinal disorders. Some probiotic supplements need to be refrigerated, so check the label and keep that in mind before you buy one. For the best results, you’ll need to commit to taking a supplement regularly (ideally daily). Once you stop taking them, the benefits will go away within one to four weeks.