While Kefir has been a staple in the diet of the inhabitants of the Caucasus mountain ranges of Eastern Europe where it originated for centuries, knowledge of this functional food and its properties in western civilization is relatively new, starting in Russia in the late 1800s early 1900s.
Kefir was first introduced to western civilization by Dr. Eli Metchnikov, a Russian scientist and Nobel Laureate who was intrigued with the exceptional good health and longevity exhibited in the populations of Bulgaria and Northern Caucasus. While he was studying these populations to identify the cause of the exceptional good health and longevity enjoyed by these peoples, he identified the consumption of Kefir as a staple in the diet as being one of the main threads these people had in common.
Dr. Metchnikoff theorized that the lactic acid bacteria (lab) in the fermented milk products consumed by these people were responsible for the health and longevity they enjoyed.
Dr. Metchnikoff believed that there was a direct connection between diseases and the microorganisms inhabiting the digestive tract and that harmful microorganism were responsible for the majority of diseases and illness. Dr. Metchnikoff theorized that lactic acid bacteria in the fermented milk successfully competed against the harmful bacteria in the digestive tract thereby limiting the ability of harmful bacteria to cause illness and disease.
Dr. Metchnikoff's studies into the function of lactic acid bacteria on the digestive tract and immune system serve as the basic foundation on which the modern studies of Probiotics are based today.