Probiotics may be a single strain or a set of different microorganisms. Kefir is an example of a probiotic that contains various types of bacteria and yeasts (Prado et al., 2015). Kefir beverage is one of the oldest fermented milk products, a natural probiotic and alcohol-lactic beverage derived from milk fermentation by kefir grains. Kefir is effective in promoting health, boosting the immune system, balancing blood pressure, treating gastrointestinal diseases, and lowering serum cholesterol levels. It also has antibacterial, antifungal, and antitumor activities