Fermented Dairy Product, Fermented Milk, Fromage Kéfir, Kéfir, Kefir Cheese, Kefir Grains, Kefir Yogurt, Kellermilch, Kjaklder Mjoklk, Lait Fermenté, Omaere, Produit Laitier Fermenté, Rob, Roba, Tarag.<br/><br/>


Overview Information

Kefir is a product made by fermenting milk.

People use kefir for indigestion, upset stomach, constipation, lactose intolerance, diarrhea caused by antibiotics, weight loss, exercise performance, bone health, and high cholesterol. It is also used to reduce levels of the bacteria Helicobacter pylori, found in association with ulcers. It is also used to reduce side effects of chemotherapy, including stomach and intestinal problems and soreness and swelling inside the mouth (oral mucositis).

How does it work?

Kefir contains actively growing bacteria and yeast. Their effect on milk results in production of enzymes and chemicals that affect the way food is digested.


Uses & Effectiveness?

Insufficient Evidence for

  • Diarrhea associated with taking antibiotics. Some research shows that a specific kefir-containing drink (Probugs, Lifeway Foods, Inc.) does not reduce diarrhea in children caused by antibiotics.
  • Stomach and intestinal problems related to use of chemotherapy. Early research shows that taking kefir during chemotherapy treatment does not reduce stomach and intestinal problems. In fact, it might make these problems slightly worse.
  • Constipation. Early research shows that taking kefir helps increase the number of bowel movements in people with constipation. It also seems to soften stools.
  • Exercise performance. Early research shows that taking kefir after exercise does not improve running ability during later exercises.
  • Ulcers caused by a bacterium called Helicobacter pylori (H. pylori). Early research shows that taking kefir along with standard treatment for H. pylori helps get rid of infections in more people than standard treatment alone.
  • High cholesterol. Early research shows that taking kefir does not lower cholesterol levels.
  • Obesity. Early research shows that eating kefir as part of a weight maintenance diet reduces body weight by a small amount in overweight or obese women. But eating low-fat milk dairy products instead of kefir as part of a similar diet seems to have the same effect.
  • Soreness and swelling inside the mouth, caused by chemotherapy (oral mucositis). Early research shows that rinsing the mouth with kefir and swallowing 250 mL of kefir twice daily for the first 5 days of chemotherapy does not prevent the development of sores inside the mouth caused by chemotherapy.
  • Osteoporosis. Early research shows that taking kefir with calcium does not improve bone strength any more than calcium alone in adults with osteoporosis.
  • Lactose intolerance.
  • Improving digestion.
  • Other conditions.
More evidence is needed to rate the effectiveness of kefir for these uses.

Side Effects

Side Effects & Safety

Kefir is POSSIBLY SAFE for most adults when taken by mouth for up to 8 weeks.

Kefir can cause side effects like bloating, nausea, intestinal cramping, and constipation, especially when use is started. Usually these side effects resolve with continued use.

Special Precautions & Warnings:

Children: Kefir is POSSIBLY SAFE for children between the ages of 1 and 5 years when taken by mouth for up to 10 days.

Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking kefir if you are pregnant or breast-feeding. Stay on the safe side and avoid use.

AIDS and other conditions that weaken the immune system: Kefir contains actively growing bacteria and yeast. There is some concern that people with a weakened immune system might be more likely to develop infections from these bacteria or yeast.

Colon cancer: In people undergoing chemotherapy for colon cancer, kefir might increase side effects such as stomach and intestinal problems, mouth sores, drowsiness, sweats, and hair loss.



Moderate Interaction

Be cautious with this combination

  • Medications that decrease the immune system (Immunosuppressants) interacts with KEFIR

    Kefir contains live bacteria and yeast. The immune system usually controls bacteria and yeast in the body to prevent infections. Medications that decrease the immune system can increase your chances of getting sick from bacteria and yeast. Taking kefir along with medications that decrease the immune system might increase the chances of getting sick.<br><nb>Some medications that decrease the immune system include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), corticosteroids (glucocorticoids), and others.



The appropriate dose of kefir depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for kefir. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

View References


  • Athanasiadis, I., Boskou, D., Kanellaki, M., and Koutinas, A. A. Low-temperature alcoholic fermentation by delignified cellulosic material supported cells of kefir yeast. J.Agric.Food Chem. 1999;47(10):4474-4477. View abstract.
  • Figler, M., Mozsik, G., Schaffer, B., Gasztonyi, B., Acs, P., Szili, B., Rab, R., and Szakaly, S. Effect of special Hungarian probiotic kefir on faecal microflora. World J Gastroenterol. 2-21-2006;12(7):1129-1132. View abstract.
  • Hertzler, S. R. and Clancy, S. M. Kefir improves lactose digestion and tolerance in adults with lactose maldigestion. J.Am.Diet.Assoc. 2003;103(5):582-587. View abstract.
  • Rabl, W., Liniger, B., Sutter, K., and Sigrist, T. [Ethanol content of Kefir water]. Blutalkohol 1994;31(2):76-79. View abstract.
  • Topuz, E., Derin, D., Can, G., Kurklu, E., Cinar, S., Aykan, F., Cevikbas, A., Disci, R., Durna, Z., Sakar, B., Saglam, S., Tanyeri, H., Deniz, G., Gurer, U., Tas, F., Guney, N., and Aydiner, A. Effect of oral administration of kefir on serum proinflammatory cytokines on 5-FU induced oral mucositis in patients with colorectal cancer. Invest New Drugs 2008;26(6):567-572. View abstract.
  • Agerbaek M, Gerdes LU, Richelsen B. Hypocholesterolaemic effect of a new fermented milk product in healthy middle-aged men. Eur J Clin Nutr 1995;49:346-52. View abstract.
  • Alm L. Effect of fermentation on lactose, glucose, and galactose content in milk and suitability of fermented milk products for lactose intolerant individuals. J Dairy Sci 1982;65:346-52. View abstract.
  • Bekar O, Yilmaz Y, Gulten M. Kefir improves the efficacy and tolerability of triple therapy in eradicating Helicobacter pylori. J Med Food. 2011;14(4):344-7. View abstract.
  • Can G, Topuz E, Derin D, Durna Z, Aydiner A. Effect of kefir on the quality of life of patients being treated for colorectal cancer. Oncol Nurs Forum. 2009;36(6):E335-42. View abstract.
  • De Vrese M, Keller B, Barth CA. Enhancement of intestinal hydrolysis of lactose by microbial beta-galactosidase (EC of kefir. Br J Nutr 1992;67:67-75. View abstract.
  • Fathi Y, Faghih S, Zibaeenezhad MJ, Tabatabaei SH. Kefir drink leads to a similar weight loss, compared with milk, in a dairy-rich non-energy-restricted diet in overweight or obese premenopausal women: a randomized controlled trial. Eur J Nutr. 2016;55(1):295-304. View abstract.
  • Marquina D, Santos A, Corpas I, et al. Dietary influence of kefir on microbial activities in the mouse bowel. Lett Appl Microbiol 2002;35:136-40. View abstract.
  • Merenstein DJ, Foster J, D'Amico F. A randomized clinical trial measuring the influence of kefir on antibiotic-associated diarrhea. Arch Pediatr Adolesc Med 2009;163:750-4. View abstract.
  • Murofushi M, Mizuguchi J, Aibara K, Matuhasi T. Immunopotentiative effect of polysaccharide from kefir grain, KGF-C, administered orally in mice. Immunopharmacology 1986;12:29-35. View abstract.
  • Murofushi M, Shiomi M, Aibara K. Effect of orally administered polysaccharide from kefir grain on delayed-type hypersensitivity and tumor growth in mice. Jpn J Med Sci Biol 1983;36:49-53. View abstract.
  • O'Brien KV, Stewart LK, Forney LA, Aryana KJ, Prinyawiwatkul W, Boeneke CA. The effects of postexercise consumption of a kefir beverage on performance and recovery during intensive endurance training. J Dairy Sci. 2015;98(11):7446-9. View abstract.
  • Richelsen B, Kristensen K, Pedersen SB. Long-term (6 months) effect of a new fermented milk product on the level of plasma lipoproteins--a placebo-controlled and double blind study (abstract). Eur J Clin Nutr 1996;50:811-5. View abstract.
  • Rimada PS, Abraham AG. Polysaccharide production by kefir grains during whey fermentation. J Dairy Res 2001;68:653-61. View abstract.
  • Schaafsma G, Meuling WJ, van Dokkum W, Bouley C. Effects of a milk product, fermented by Lactobacillus acidophilus and with fructo-oligosaccharides added, on blood lipids in male volunteers. Eur J Clin Nutr 1998;52:436-40. View abstract.
  • Schaafsma G, Meuling WJ, van Dokkum W, Bouley C. Effects of a milk product, fermented by Lactobacillus acidophilus and with fructo-oligosaccharides added, on blood lipids in male volunteers. Eur J Clin Nutr 1998;52:436-40. View abstract.
  • Shiomi M, Sasaki K, Murofushi M, Aibara K. Antitumor activity in mice of orally administered polysaccharide from Kefir grain. Jpn J Med Sci Biol 1982;35:75-80. View abstract.
  • Simova E, Beshkova D, Angelov A, et al. Lactic acid bacteria and yeasts in kefir grains and kefir made from them. J Ind Microbiol Biotechnol 2002;28:1-6. View abstract.
  • St-Onge MP, Farnworth ER, Savard T, et al. Kefir consumption does not alter plasma lipid levels or cholesterol fractional synthesis rates relative to milk in hyperlipidemic men: a randomized controlled trial [ISRCTN10820810]. BMC Complement Altern Med 2002;2:1. View abstract.
  • Thoreux K, Schmucker DL. Kefir milk enhances intestinal immunity in young but not old rats. J Nutr 2001;131:807-12. View abstract.
  • Tu MY, Chen HL, Tung YT, Kao CC, Hu FC, Chen CM. Short-term effects of kefir-fermented milk consumption on bone mineral density and bone metabolism in a randomized clinical trial of osteoporotic patients. PLoS One. 2015;10(12):e0144231. View abstract.
  • Turan I, Dedeli Ö, Bor S, Ilter T. Effects of a kefir supplement on symptoms, colonic transit, and bowel satisfaction score in patients with chronic constipation: a pilot study. Turk J Gastroenterol. 2014;25(6):650-6. View abstract.

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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

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© Therapeutic Research Faculty 2018.