Template:POTD/2022-05-15
Élie Metchnikoff (15 May 1845 – 15 July 1916) was a Russian and French zoologist of Romanian noble ancestry and Ukrainian Jewish origin, best known for his pioneering research on immunology, for which he was jointly awarded the 1908 Nobel Prize in Physiology or Medicine with Paul Ehrlich. Metchnikoff developed a theory that ageing is caused by toxic bacteria in the gut and that consumption of lactic acid could prolong life. Supporters of life extension celebrate 15 May as Metchnikoff Day. This photograph of Metchnikoff working in a laboratory was taken in 1913.Photograph credit: Agence Rol; restored by Adam Cuerden