Kefir health benefit, probiotic content
March 22 2017 by
Ray Sahelian, M.D.


Kefir is a fermented milk beverage. It is an ancient drink from the Caucasus Mountains that looks like liquid yogurt. Traditional kefir is tart - even sour - and contains a bit of carbonation and some alcohol from the fermentation. However, much of the kefir sold commercially in the United States is neither carbonated nor alcoholic. I personally enjoy drinking kefir, especially the ones that have raspberry or strawberry. The problem with it is that it is so tasty, one can easily keep drinking a glass several times a day which can pack a lot of calories.


How is Kefir made?
Kefir is made by adding a live culture - called kefir "grains" - from a previous batch of kefir to room-temperature milk (usually from a cow, goat or sheep. The cultures are a combination of bacteria and yeasts, usually lactobacillus acidophilus and Saccharomyces kefir.
   The milk fermentation is achieved by the of kefir grains, a cluster of microorganisms held together by a polysaccharide matrix named kefiran. Kefir grains are an example of symbiosis between yeast and bacteria. They have been used over years to produce kefir, a fermented beverage that is consumed all over the world, although its origin is Caucasian. A vast variety of different species of organisms forming the kefir grains, comprising yeast and bacteria, have been isolated and identified. Kefir is a probiotic food. Probiotics have shown to be beneficial to health, being presently of great interest to the food industry. Kefir has been accredited with antibacterial, antifungal and antitumoural activities among other beneficial attributes.

Benefit of Kefir

kefir is a probiotic, which means it contains "friendly" bacteria. Kefir also contains calcium and protein. The viable lactic acid bacteria in fermented milk products, such as yoghurt and kefir, have been associated with increased lactose tolerance, a well-balanced intestinal microflora, antimicrobial activity, stimulation of the immune system and antitumoural, anticholesterolaemic and antioxidative properties in human subjects. A small amount of kefir a day or a few times a week is fine, but I don't think ingesting a great deal of milk products on a daily basis is very healthy.


Cancer prevention?
Arch Iran Medicine. 2015. Kefir and Cancer: A Systematic Review of Literatures. Some studies have suggested chemopreventive effects of kefir, a fermented milk product, on carcinogenesis. The aim of this review study was to evaluate the scientific evidence for effects of kefir on cancer prevention and treatment. We systematically searched for all relevant studies published before June 2015, using PubMed, Google scholar, Cochrane and Science Direct, SID, MedLib and Srlst databases. Relevant studies were reviewed based on systematic review (PRISMA) guidelines. From a total of 2208 papers obtained at the initial database search, 11 publications including 7in vitro and 4 experimental studies were eligible. In vitro studies on breast, colon, skin and gastric cancers and leukemia cell lines and experimental studies on different sarcomas consistently showed beneficial effects of kefir on cancer prevention and treatment. The results of this systematic review suggest that kefir may be associated with cancer prevention and it also has beneficial effects in cancer treatment. This protection may be associated with kefir bioactive components including peptides, polysaccharides and sphingolipids.


Int J Oncology. 2014. Apoptotic effect of a novel kefir product, PFT, on multidrug-resistant myeloid leukemia cells via a hole-piercing mechanism. We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics. Results suggest that PFT may act as a potential therapy for the treatment of MDR leukemia.