Recently, beneficial effects of functional dairy products which are supported with many studies attract consumer interest. At this point kefir; which has a very old history, is a fermented milk product obtained as a result of alcohol and lactic acid fermentation via using grain or culture. Besides being produced by milk, synthesis of certain vitamins, partial disintegration of protein and lactose during the production increase the nutritional value of kefir. Many studies particularly about gastrointestinal diseases and health-related properties of kefir like; ability to control certain types of cancer, cholesterol-lowering effect and effects on the immune system had carried out and positive results were achieved