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Katherine Zeratsky, R.D., L.D.
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Katherine Zeratsky, R.D., L.D.
Katherine Zeratsky, R.D., L.D.
As a specialty editor for the Food & Nutrition Center, Katherine Zeratsky helps you sort through the facts and figures, the fads and the hype to learn more about nutrition and diet.
A Marinette, Wis., native, she is certified in dietetics by the state of Minnesota and the American Dietetic Association. She has been with Mayo Clinic since 1999.
She is active in nutrition-related curriculum and course development in pediatrics at Mayo Clinic Rochester and nutrition education related to the physiology and recommended intakes for premature infants.
Other areas of interest include breast milk and formula safety, neonatal feeding, and nutrition for breast-feeding mothers.
She graduated from the University of Wisconsin-Madison, served a dietetic internship at the University of Iowa Hospitals and Clinics, and worked as a registered dietitian and health risk counselor at ThedaCare of Appleton, Wis., before joining the Mayo Clinic staff.
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Question
Prebiotics: What are they?
What are prebiotics? How are they different from probiotics, and what health benefits do they offer?
Answer
from Katherine Zeratsky, R.D., L.D.
Prebiotics are nondigestible nutrients that are used as an energy source by certain beneficial bacteria that naturally live in your intestines. Prebiotics are sometimes known as fermentable fiber.
Probiotics, in contrast, are the beneficial, or friendly, bacteria themselves. By acting as a food source, prebiotics give the probiotic bacteria a chance to exert their influence. These friendly bacteria may have several health benefits, from aiding digesting to boosting immunity. But stress, a poor diet, certain medical conditions, medications and other factors may decrease the number of healthy bacteria. Eating a diet that includes prebiotics and probiotics may help restore these friendly bacteria.
The role of prebiotics in the treatment of disease is controversial, and more studies are needed to determine their usefulness. But preliminary evidence shows that prebiotics may have a role in:
- Improving antibiotic-associated diarrhea
- Improving traveler's diarrhea
- Improving gastroenteritis
- Normalizing bowel function
- Improving colitis
- Reducing irritable bowel problems
- Aiding calcium absorption
- Boosting your immune system
Prebiotics occur naturally in a variety of foods, especially high-fiber foods, including certain fruits, vegetables and grains. The main food sources of prebiotics include:
- Artichokes
- Bananas
- Barley
- Berries
- Chicory
- Dairy products
- Flax
- Garlic
- Greens, such as dandelion greens, chard and kale
- Honey
- Leeks
- Legumes
- Onions
- Wheat and whole grains, such as oatmeal
Prebiotics also are added to some dietary supplements and some processed foods, such as yogurt, drink mixes and meal-replacement bars. Read food labels and claims or seek out manufacturer Web sites to help identify which products contain prebiotics. But keep in mind that not all products with naturally occurring prebiotics are labeled that way. Prebiotic supplements can be sprinkled on your food, stirred into beverages, or taken as capsules or tablets that you swallow or chew.
There's no specific guideline on how many grams of prebiotics to consume. Some studies suggest that you should get 3 to 8 grams a day to get the full benefits. In some cases, use of prebiotics may cause intestinal gas. As always, check with your doctor before taking any dietary or herbal supplements to make sure they're safe for your situation.
Next questionCandida cleanse: What does it treat?
- Mahan K, et al. Krause's Food & Nutrition Therapy. 12th ed. St. Louis, Mo.: Saunders Elsevier; 2008.
- Greenfield RH. Prescribing probiotics. In: Rakel D. Integrative Medicine. 2nd ed. Philadelphia, Pa.: Saunders Elsevier; 2007. http://www.mdconsult.com/das/book/body/164986373-2/887715178/1494/151.html . Accessed Sept. 14, 2009.
- Douglas L, et al. Probiotics and prebiotics in dietetics practice. Journal of the American Dietetic Association. 2008;108:510.
- Duyff RL. American Dietetic Association Complete Food and Nutrition Guide. 3rd ed. Hoboken, N.J.: John Wiley & Sons; 2006.
- Prebiotics: A consumer guide for making smart choices. International Scientific Association for Probiotics and Prebiotics. http://www.isapp.net/docs/Consumer_Guidelines-prebiotic.pdf. Accessed Sept. 14, 2009.
- Preidis G, et al. Targeting the human microbiome with antibiotics, probiotics, and prebiotics: Gastroenterology enters the metagenomics era. Gastroenterology. 2009;136:2015.
- Gibson G. Prebiotics as gut microflora management tools. Journal of Clinical Gastroenterology. 2008;42(suppl):S75.
- Bauer BA (expert opinion). Mayo Clinic, Rochester, Minn. Sept. 30, 2009.
- Picco MF (expert opinion). Mayo Clinic, Rochester, Minn. Oct. 13, 2009.
- Zeratsky KA (expert opinion). Mayo Clinic, Rochester, Minn. Oct. 8, 2009.
