Kefir is a fermented milk drink made from cow, goat, or sheep milk that is cultured with kefir grains, which are a combination of bacteria and yeasts. This beverage is known for its probiotic properties, enhancing gut health, and has been consumed for centuries in various cultures. The beneficial microorganisms present in kefir contribute not only to its unique flavor and texture but also to its health benefits, making it a prominent example of beneficial microorganisms in food production.