Kefir

Last Editorial Review: 6/11/2021
Other Name(s):

Fermented Dairy Product, Fermented Milk, Fromage Kéfir, Kéfir, Kefir Cheese, Kefir Grains, Kefir Yogurt, Lait Fermenté, Produit Laitier Fermenté.

Overview

Kefir is a product made by fermenting milk.

People use kefir for poor digestion, upset stomach, lactose intolerance, diarrhea following treatment with antibiotics, and high cholesterol.

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.

QUESTION

Next to red peppers, you can get the most vitamin C from ________________. See Answer

Uses & Effectiveness

Likely Ineffective for...

Insufficient Evidence to Rate Effectiveness 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.
  • 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.
  • Lactose intolerance.
  • Improving digestion.
  • Other conditions.
More evidence is needed to rate the effectiveness of kefir for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

Kefir is POSSIBLY SAFE for most adults when taken by mouth for up to 6 months.

Kefir can cause intestinal cramping and constipation, especially when use is started.

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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.

Interactions


Medications that decrease the immune system (Immunosuppressants)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

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.

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.


Disulfiram (Antabuse)Interaction Rating: Minor Be cautious with this combination.Talk with your health provider.

Kefir might contain alcohol. The body breaks down alcohol to get rid of it. Disulfiram (Antabuse) decreases the break-down of alcohol. Taking kefir along with disulfiram (Antabuse) can cause a pounding headache, vomiting, flushing, and other unpleasant reactions. Don't drink any alcohol if you are taking disulfiram (Antabuse).

Dosing

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.

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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.

Barfod, G. [Emergency admission for suspected cancer of the colon of a patient suffering from diarrhea due to Kefir]. Ugeskr.Laeger 2-6-1984;146(6):433. 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.

Gulmez, M. and Guven, A. Survival of Escherichia coli O157:H7, Listeria monocytogenes 4b and Yersinia enterocolitica O3 in different yogurt and kefir combinations as prefermentation contaminant. J.Appl.Microbiol. 2003;95(3):631-636. 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.

Osada, K., Nagira, K., Teruya, K., Tachibana, H., Shirahata, S., and Murakami, H. Enhancement of interferon-beta production with sphingomyelin from fermented milk. Biotherapy 1993;7(2):115-123. View abstract.

Rabl, W., Liniger, B., Sutter, K., and Sigrist, T. [Ethanol content of Kefir water]. Blutalkohol 1994;31(2):76-79. View abstract.

Santos, A., San Mauro, M., Sanchez, A., Torres, J. M., and Marquina, D. The antimicrobial properties of different strains of Lactobacillus spp. isolated from kefir. Syst.Appl.Microbiol. 2003;26(3):434-437. 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.

De Vrese M, Keller B, Barth CA. Enhancement of intestinal hydrolysis of lactose by microbial beta-galactosidase (EC 3.2.1.23) of kefir. Br J Nutr 1992;67:67-75. View abstract.

Ebringer, L., Ferencik, M., and Krajcovic, J. Beneficial health effects of milk and fermented dairy products--review. Folia Microbiol (Praha) 2008;53(5):378-394. View abstract.

Forssen, K. M., Jagerstad, M. I., Wigertz, K., and Witthoft, C. M. Folates and dairy products: a critical update. J Am Coll Nutr 2000;19(2 Suppl):100S-110S. 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.

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.