Kefir

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    Last Updated: October 6, 2024

    Kefir is a probiotic fermented milk drink made with a symbiotic culture of bacteria and yeasts. It may benefit oral health, may be a useful adjunct to stomach ulcer treatment, and may offer slight benefits to blood sugar. On the other hand, drinking kefir makes chemo side effects worse for some cancer patients. Since it contains live, active bacteria and yeasts, kefir should be used with caution by anyone with a compromised or weakened immune system.

    What is kefir?

    Kefir is a probiotic fermented milk drink made with multiple cultures of lactic acid bacteria and yeasts. There is no single starter culture, and the bacteria and yeasts vary quite a bit between different brews.[1][2]

    What are kefir's main benefits?

    The human clinical trials on kefir to date are all small. Between the small trial sizes and the massive variation in kefirs, there isn’t strong evidence that whichever kefir you take will have any given effect on you. On the other hand, if you’re a generally healthy adult, kefir is unlikely to hurt you, and may benefit your oral health.

    Kefir may also be a useful adjunct to a common treatment for stomach ulcers, and for people with type 2 diabetes, regular kefir consumption may give slight improvements to blood sugar and glycated hemoglobin (but not enough to be considered a treatment).

    What are kefir's main drawbacks?

    • Kefir has roughly the same caloric content as the milk it was brewed from, and is often additionally flavored and sweetened.
    • As it contains live, active cultures, kefir should be taken with caution by some.
    • Kefir is lower-lactose than milk, but may still contain enough lactose to trigger symptoms of lactose intolerance.[3]
    • Kefir grains can, rarely, be contaminated with pathogenic fungi or bacteria.[4]

    How is kefir taken?

    Kefir can be drunk with meals, or alone. Kefir is also used as an ingredient in several cuisines, just as other fermented milk products (yogurt, sour cream) are. When used as a probiotic, kefir shouldn’t be cooked, because that will kill the beneficial bacteria. As with other fermented milk products, there is no recommended daily minimum or maximum for kefir consumption.

    How does kefir work?

    Many of the bacteria in kefir are known probiotic species.[5] The polysaccharides produced by the kefir cultures may also be bioactive.[6]

    What are other names for Kefir

    Note that Kefir is also known as:
    • kefyr
    • kephir
    • kefier
    Kefir should not be confused with:
    • kefiran
    • water kefir
    • tibicos
    • yogurt
    • kumis
    • labneh

    Research Breakdown

    References

    1. ^Damiana D Rosa, Manoela M S Dias, Łukasz M Grześkowiak, Sandra A Reis, Lisiane L Conceição, Maria do Carmo G PeluzioMilk kefir: nutritional, microbiological and health benefitsNutr Res Rev.(2017 Jun)
    2. ^Nor Farahin Azizi, Muganti Rajah Kumar, Swee Keong Yeap, Janna Ong Abdullah, Melati Khalid, Abdul Rahman Omar, Mohd Azuraidi Osman, Sharifah Alawieyah Syed Mortadza, Noorjahan Banu AlitheenKefir and Its Biological ActivitiesFoods.(2021 May 27)
    3. ^Steven R Hertzler, Shannon M ClancyKefir improves lactose digestion and tolerance in adults with lactose maldigestionJ Am Diet Assoc.(2003 May)
    4. ^Analy Machado de Oliveira Leite, Marco Antonio Lemos Miguel, Raquel Silva Peixoto, Alexandre Soares Rosado, Joab Trajano Silva, Vania Margaret Flosi PaschoalinMicrobiological, technological and therapeutic properties of kefir: a natural probiotic beverageBraz J Microbiol.(2013 Oct 30)
    5. ^Conor Slattery, Paul D Cotter, Paul W O'TooleAnalysis of Health Benefits Conferred by Lactobacillus Species from KefirNutrients.(2019 Jun 1)
    6. ^Maria R Prado, Lina Marcela Blandón, Luciana P S Vandenberghe, Cristine Rodrigues, Guillermo R Castro, Vanete Thomaz-Soccol, Carlos R SoccolMilk kefir: composition, microbial cultures, biological activities, and related productsFront Microbiol.(2015 Oct 30)