You don't necessarily need probiotics — a type of "good" bacteria — to be healthy. However, these microorganisms might help with digestion and offer protection from harmful bacteria, just as the existing "good" bacteria in your body already do.
Prebiotics are nondigestible carbohydrates that act as food for probiotics. When probiotics and prebiotics are combined, they interact beneficially. Fermented dairy products, such as yogurt and kefir, are considered synbiotic because they contain live bacteria and the fuel they need to thrive.
Probiotics are in foods such as yogurt and sauerkraut; prebiotics are in whole grains, bananas, onions, garlic, soybeans and artichokes. In addition, probiotics and prebiotics are added to some foods and available as dietary supplements.
Although more research is needed, there's evidence that probiotics might help:
- Treat diarrhea, especially after taking certain antibiotics
- Treat irritable bowel syndrome
- Speed treatment of certain intestinal infections
- Prevent or reduce the severity of colds and flu
- Ease allergic disorders such as eczema and hay fever
Probiotics and prebiotics are also being studied for effectiveness and safety in other diseases, such as diabetes, cancer and heart disease.
Side effects are rare, and most healthy adults can safely add foods that contain prebiotics and probiotics to their diets. If you're considering taking supplements, check with your doctor to be sure they're right for you.
Oct. 17, 2017
See more Expert Answers
- Probiotics: In depth. National Center for Complementary and Alternative Medicine. https://nccih.nih.gov/health/probiotics/introduction.htm. Accessed Aug. 1, 2017.
- Prebiotics and probiotics: Creating a healthier you. Academy of Nutrition and Dietetics. http://www.eatright.org/resource/food/vitamins-and-supplements/nutrient-rich-foods/prebiotics-and-probiotics-the-dynamic-duo. Accessed Aug. 1, 2017.
- Sartor RB. Probiotics for gastrointestinal diseases. https://www.uptodate.com/content/search. Accessed Aug. 1, 2017.
- Hao Q, et al. Probiotics for preventing acute upper respiratory tract infections. Cochrane Database of Systematic Reviews. http://onlinelibrary.wiley.com/wol1/doi/10.1002/14651858.CD006895.pub3/abstract. Accessed Aug. 1, 2017.