Health library

Oct. 31, 2022—You've probably heard of probiotics. And you might have seen them in the supermarket or pharmacy. But what are probiotics exactly? Are they good for your health? And should you join the millions of Americans who already take them?

A probiotic primer

Probiotics are live microorganisms, such as bacteria and yeasts. You can find them in fermented foods, like yogurt. Or they may be added to some food products and in dietary supplements.

Why take them? Some research signals that they may help with certain health conditions. According to the National Institutes of Health (NIH), some conditions probiotics may help prevent or treat include:

• Antibiotic-associated diarrhea. People younger than 65 may avoid this by taking probiotics.
• Necrotizing enterocolitis in premature infants.
• Infant colic.
• Periodontal disease.
• Constipation.
• Atopic dermatitis (eczema). Some studies showed that taking probiotics during pregnancy and infancy might reduce the risk of developing the condition and lower the severity of symptoms. Effects vary, depending on the strain of probiotics used and when they were taken.

According to the American Gastroenterological Association (AGA), certain probiotics, in combination with usual treatments, can also help ease pouchitis, a side effect from ulcerative colitis surgery.

However, the AGA warns that people should not take probiotics for certain conditions, including:

• Clostridium difficile infection.
• Crohn's disease.
• Ulcerative colitis.
• Irritable bowel syndrome.

Feasting on probiotics

Probiotics mainly act in the digestive tract. There, they can affect your gut microbiome, which is made up of many microorganisms (primarily bacteria) that live in your large intestine. Eating or drinking enough probiotic-containing foods or drinks:

• Helps protect your digestive tract from harmful microorganisms.
• Improves your digestion.
• May provide additional health benefits as well.

To get more probiotics in your diet, pay attention to the food label, which may list the live microorganisms that are probiotics. According to the NIH, heated and processed fermented foods, like sourdough bread and most pickles, do not have live microorganisms.

Also, until more research is done, it's not clear if foods like apple cider vinegar, cheese, kimchi, kombucha, miso and sauerkraut have probiotic benefits.

Taking supplements

If you're tempted to try a probiotic supplement, know that these dietary supplements contain a wide variety of microorganisms and amounts. And since many probiotic supplements have not been studied, their health benefits, if any, aren't known.

Are probiotics right for me?

Probiotics are generally considered safe in healthy people. They may cause gas, but they rarely cause infections or other health problems. But it is always a good idea to check with your primary care provider or gastroenterologist before taking a probiotic supplement or adding a lot of probiotic foods to your diet—especially if you have a serious illness or a weak immune system. These medical professionals can advise you on whether probiotics are a good choice for you.

Separate fact from fiction by taking our alternative medicine quiz.