Ilya Ilyich Mechnikov

Ilya Ilyich Mechnikov (Илья Ильич Мечников, also known as Elie Metchnikoff, May 16, 1845, near Kharkiv, Ukraine – July 16, 1916, Paris) was a Russian microbiologist best remembered for his pioneering research into the immune system. Mechnikov received the Nobel Prize in Medicine in 1908, for his work on phagocytosis.

Mechnikov was born in a village near Kharkov in the Russian Empire (now Kharkiv, Ukraine), the youngest son of an officer in the Russian Imperial Guard of Russian ethnicity. His elder brother Lev became a prominent geographer and sociologist. Ilya was raised predominantly by his Jewish mother, née Nevakhovich, and had a passion for natural history. When Charles Darwin’s book, The Origin of Species was published, he was eager to believe the theory of evolution.

He went to Kharkov University to study natural sciences, completing his four-year degree in just two years. He then went to Germany to study marine fauna on the small North Sea island of Heligoland and then at the University of Giessen, University of Göttingen and then at Munich Academy. In 1867 he returned to the Russian Empire to the appointment of docent at the new University of Odessa, followed by an appointment at the University of St. Petersburg. In 1870 he returned to Odessa to take up the appointment of Titular Professor of Zoology and Comparative Anatomy.

His first wife, Ludmila Feodorovovna, suffered from tuberculosis, of which she died in 1873. Her death, combined with other problems, caused Mechnikov to unsuccessfully attempt suicide, taking a large dose of opium. He married again in 1875, and his second wife, Olga, caught typhoid in 1880, causing Mechnikov to again attempt suicide—this time by injecting himself with relapsing fever, which didn't kill him, but made him very ill. He became interested in the study of microbes, and especially the immune system. In 1882 he resigned his position at Odessa University and set up a private laboratory at Messina to study comparative embryology, where he discovered phagocytosis after experimenting on the larvae of starfish. His theories were radical: certain white blood cells could engulf and destroy harmful bodies such as bacteria. The ‘sophisticated’ microbe hunters in the West — Pasteur, Behring, etc. — scorned the Russian and his humble theory.

Mechnikov returned to Odessa as director of an institute set up to carry out Louis Pasteur's vaccine against rabies, but due to some difficulties left in 1888 and went to Paris to seek Pasteur's advice. Pasteur gave him an appointment at the Pasteur Institute, where he remained for the rest of his life.

Later vindicated, Mechnikov's work on phagocytes won him the Nobel Prize in 1908. He worked with Émile Roux on an ointment that would prevent people from contracting syphilis, an STD.

Mechnikov also developed a theory that aging is caused by toxic bacteria in the gut and that lactic acid could prolong life. Based on his theory, he drank sour milk every day. He died in 1916 at 71 years of age (well above the average life expectancy at the time), after writing three books: Immunity in Infectious Diseases, The Nature of Man, and The Prolongation of Life: Optimistic Studies.

It was the last of these works, along with Metchnikoff's studies into the potential life-lengthening properties of lactic acid bacteria (LAB) that inspired Japanese scientist Minoru Shirota to begin investigating the causal relationship between bacteria and good intestinal health. Convinced that a healthy balance of intestinal bacteria held the key to man's general well-being, Shirota dedicated his life and work to isolating a strain of LAB which would pass into the intestines, positively contributing to the balance of gut flora. In 1935, he succeeded in cultivating a unique bacterium, sufficiently robust to bypass the acidic environment of the stomach and enter the intestines directly. He placed this pioneering strain into a fermented milk drink in order to make its benefits accessible to all - this drink remains available worldwide today (in a recipe almost unchanged from Shirota's original formula) as the Yakult drink.