Elie Metchnikoff was born on May 16, 1845, near Kharkoff, Ukraine. He studied natural sciences at the University of Kharkoff. After graduating from Kharkoff, Metchnikoff went to the University of Giessen, Germany, to study marine biology. In 1865, he discovered intercellular digestion in a flatworm, which would structure his later research.
In 1867, he returned to Russia to teach at the University of Odessa. Shortly, after arriving at the University of Odessa he joined the faculty at the University of St. Petersburg. In 1870, however, Metchnikoff would once again return to the University of Odessa where he was appointed Titular Professor of Zoology and Comparative Anatomy. In 1883, he left Odessa and traveled to Messina to work privately in a small laboratory; it was in Messina that Metchnikoff revealed the phenomenon of phagocytosis. After discovering phagocytosis, Metchnikoff returned to Odessa, and in 1883 published his first paper about his work.
In 1888, Metchnikoff left Odessa, and took a position at the Pasteur Institute laboratory in Paris. In 1904, after working several years at the Pasteur Institute, Metchnikoff became the deputy director. He remained at the Pasteur Institute for the remainder of his career.
Eli Metchnikoff was the first of two Jews, along with Paul Ehrlich, to receive the Nobel Prize for Medicine in 1908 for their research on cellular immunity. He was awarded the honor for the theory of phagocytosis, which demonstates the process of how specific white blood cells can break down harmful bacteria in the body.
He also identified an apparent link between acidophilus-type bacteria and extended lifespan for humans. Acidophilus is a nutritional supplement product, which contains a given bacteria. He was pivotal in starting the relatively modern discipline of probiotics (are dietary supplements containing potentially benefical bacteria and yeasts. Also, along with P.P.É. Roux, they researched the affects of using calomel ointment to treat syphilis.
Metchnikoff’s works include L'Immunité dans les Maladies Infectieuses (Immunity in Infectious Diseases, 1901), in which he elaborates on his research of phagocytosis, and The Nature of Man (1938). He received numerous other awards and recognition for his work including an honorary Doctorate of Science from the University of Cambridge and an honorary membership of the Academy of Medicine in Paris.
He died on July 16, 1916, in Paris, at the age of 70.