Kefir As a Living Food: Fermentation, Function, and Health

Abstract

Milk kefir and water kefir are the two main varieties of kefir, a fermented beverage recognized for its probiotic qualities and health advantages. People in the mountainous area between Europe and Asia have been consuming kefir milk for thousands of years. The process of making milk kefir involves fermenting milk (often from cows, goats, or sheep) with milk kefir grains, which are symbiotic cultures of yeasts and lactic acid bacteria. A tangy, creamy beverage full of vitamins, probiotics, and bioactive components is the end product. By fermenting sugar water or fruit juice with water kefir grains, which have a distinct microbial population suited to a non-dairy environment, water kefir, on the other hand, is a dairy-free substitute. In addition to providing probiotic advantages, this results in a mildly carbonated, sweet-tart beverage that is appropriate for vegetarians and others who are lactose intolerant. Both varieties of kefir support intestinal health. These grains are inhabited by a varied symbiotic ecosystem of yeasts, lactic acid bacteria, acetic acid bacteria, and other microorganisms. In kefir grains, the most prevalent bacteria are lactic acid bacterial taxa, such as Lactobacillus, Lactococcus, Leuconostoc, and Streptococcus. These grains also frequently contain yeast species such as Candida, Saccharomyces, Kluyveromyces, Kazachstania, and Pichia. Kefir drinks have been linked to several significant health benefits, including as improved lactose digestion, anti-carcinogenic, anti-hypertensive, and anti-diabetic properties, among others. In addition, kefir supports intestinal health by keeping the intestinal flora in balance. All of these health benefits are brought about by the kefir bacteria, their interactions, and the metabolic products they produce throughout the fermentation process. Thus, this review aims to provide information on fermentation, function, and health benefits of kefir.