Russian microbiologist Elie Metchnikoff (1845-1916) was the first to associate the large amounts of fermented dairy products with the good health and longevity of Bulgarians back in 1907. He proposed that the acid-producing organisms in fermented dairy products could prevent what he called "fouling" in the large intestine. He believed if eaten regularly, these foods could lead to a longer, healthier life. One version of the Old Testament even attributes Abraham's long life — 175 years — to the "consumption of sour milk." Fermented milk products may have also been used to treat illnesses of the digestive tract during Roman times.