Probiotics and prebiotics are a hot topic these days. You’ve likely seen many ads on television and online for supplements and foods that promise to deliver helpful bacteria and their benefits. Here’s what you need to know before purchasing these products.

Your large intestine contains 100 trillion "good" bacteria that are essential to health. Called the microbiome, these beneficial microbes help maintain healthy bowel function, and may even help with like inflammatory bowel disease. Research suggests they may even play a role in regulating weight and mood.

Everyone starts with their unique microbiome at birth. We add to these through the foods we eat.

Here Are Some of the Best Ways to Add Healthful Bacteria to Your Microbiome:

• Yogurt and kefir. Be sure to look for the words "live and active cultures" on the label, to make sure you are getting live cultures.
• Fermented foods. Beneficial microbes are the "cooks" for some familiar foods. For example, they turn cabbage into sauerkraut, cucumbers into sour pickles, soybeans into miso, and sweetened tea into kombucha. When if the products have been pasteurized—as most packaged fermented foods are—the microbes will be dead. The best solution is to buy from Delis where they do the pickling themselves or natural food stores that carry fermented foods. Or make your own; you can find clear and easy instructions in books and online.

There are also probiotic supplements on the market, of course. But it’s not easy to sift through them and find exactly what you need.

Here’s What You Need to Know:

• Usually, these products contain just a few bacterial strains, compared with 3,000 or so strains in your gut. And not all gut bacteria are alike.
• Specific bacterium play specific roles in the body, so if you’re trying to treat a specific condition, like irritable bowel syndrome or diarrhea, you need to find the right ones with documented benefits for that condition. In 2020, the American Gastroenterological Association released guidelines for the use of probiotics.
• Experts point out that good evidence for taking probiotic supplements exists for only a handful of conditions. For general health, look for brands that contain both Lactobacillus and Bifidobacterium.

Here is How You Can Help Your Body Produce Healthy Gut Bacteria:

• Include plenty of foods rich in insoluble fiber in your diet. You’ll find them in whole-grain products such as oatmeal and whole-grain bread, as well as in vegetables like asparagus, leeks, onions, and garlic, and starchy vegetables like sweet potatoes and corn. Beans, lentils, and peas are also good sources.
• Limit sugar, saturated, fat, and processed foods. These can deplete the good bacteria in the gut. As always, try to stick with whole, unprocessed foods.