Kefir: a multifaceted fermented dairy product

Probiotics Antimicrob Proteins. 2014 Dec;6(3-4):123-35. doi: 10.1007/s12602-014-9168-0.


Kefir is a fermented dairy beverage produced by the actions of the microflora encased in the "kefir grain" on the carbohydrates in the milk. Containing many bacterial species already known for their probiotic properties, it has long been popular in Eastern Europe for its purported health benefits, where it is routinely administered to patients in hospitals and recommended for infants and the infirm. It is beginning to gain a foothold in the USA as a healthy probiotic beverage, mostly as an artisanal beverage, home fermented from shared grains, but also recently as a commercial product commanding shelf space in retail establishments. This is similar to the status of yogurts in the 1970s when yogurt was the new healthy product. Scientific studies into these reported benefits are being conducted into these health benefits, many with promising results, though not all of the studies have been conclusive. Our review provides an overview of kefir's structure, microbial profile, production, and probiotic properties. Our review also discusses alternative uses of kefir, kefir grains, and kefiran (the soluble polysaccharide produced by the organisms in kefir grains). Their utility in wound therapy, food additives, leavening agents, and other non-beverage uses is being studied with promising results.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Cultured Milk Products / chemistry*
  • Cultured Milk Products / microbiology
  • Fermentation
  • Humans
  • Lactobacillaceae / classification
  • Lactobacillaceae / genetics
  • Lactobacillaceae / isolation & purification
  • Lactobacillaceae / metabolism*
  • Probiotics / chemistry
  • Probiotics / therapeutic use