Kefir is a fermented milk drink similar to a thin yogurt or ayran, made by fermenting the milk of cows, goats, or sheep with kefir grains-a symbiotic culture of bacteria and yeast that looks like small cauliflower-like clusters

. The fermentation process converts lactose in the milk into lactic acid, giving kefir a tangy, slightly sour flavor and a thinner, pourable consistency compared to yogurt

. Originating thousands of years ago in the Caucasus Mountains of Eastern Europe and nearby regions, kefir has a long history and is traditionally consumed as a common beverage throughout western Eurasia

. The word "kefir" comes from the Turkish word "keif," meaning "good feeling," reflecting its reputed health benefits

. Kefir is rich in probiotics-beneficial bacteria such as lactobacillus, lactococcus, and streptococcus-that support gut health and digestion

. It also provides significant nutrients including protein, calcium, B vitamins, phosphorus, magnesium, and vitamin D

. Because of the fermentation, kefir is lower in lactose than regular milk and may be easier to digest for some people with lactose intolerance

. In summary, kefir is a nutritious, probiotic-rich fermented dairy drink with a tangy taste and smooth, drinkable texture, valued both for its flavor and potential digestive and immune health benefits