In the early 1900s, Metchnikoff promoted the consumption of the yoghurt bacteria Lactobacillus bulgaricus because he observed that the yoghurt consuming Bulgarians appeared to have healthier and more long-lived people that other groups he studied.
Metchnikoff developed and perpetuated the theory that not only does the intestinal microbiota control the outcome of infection by enteric pathogens, but it also regulates the natural chronic toxemia which plays a major role in aging and mortality.
In 1884, Metchnikoff announced a novel theory of the protective role of inflammation. He discovered phagocytosis and recognized the importance of this phenomenon in the defense against infections.
The discovery of phagocytosis by Metchnikoff marks the birth of immunology. His early research was concerned with the identification of primordial embryologic structures and functions that could link them to the evolution of species; in other words, he was searching for a link between ontogeny and phylogeny.
In 1908, the Nobel Prize in Physiology and Medicine was awarded jointly to Élie Metchnikoff and Paul Ehrlich who stressed the role of humoral antibodies on immunity.
Élie Metchnikoff contributions to immunology
