Lina Zeldovich writes: What do Jamie Lee Curtis, gut bacteria, and a long forgotten Russian scientist have in common? Why, yogurt, of course. But wait, the answer is not that easy. Behind it stretches a tale that shows you can never predict cultural influence. It wends its way through the Pasteur Institute, the Nobel Prize, one of the hottest fields of scientific research today, the microbiome, and one of the trendiest avenues in nutrition, probiotics. It all began in the 19th century with a hyperactive kid in Russia who had a preternatural ability to connect dots where nobody saw dots at all.
When Ilya Metchnikoff was 8 and running around on his parents’ Panassovka estate in Little Russia, now Ukraine, he was making notes on the local flora like a junior botanist. He gave science lectures to his older brothers and local kids whose attendance he assured by paying them from his pocket money. Metchnikoff earned the nickname “Quicksilver” because he was in constant motion, always wanting to see, taste, and try everything, from studying how his father played card games to learning to sew and embroider with the maids. His wife later wrote in The Life of Ellie Metchnikoff that Metchnikoff asked the “queerest” questions, often exasperating his caretakers. “He could only be kept quiet when his curiosity was awakened by observation of some natural objects such as an insect or a butterfly.”
At 16, Metchnikoff borrowed a microscope from a university professor to study the lower organisms. Darwin’s On the Origin of Species shaped his comparative approach to science during his university years — he viewed all organisms, and physiological processes that took place in them, as interconnected and related.
That ability led him to the discovery of a particular cell and enabled him to link digestive processes in primitive creatures to the human body’s immune defenses. In lower organisms, which lack the abdominal cavity and intestines, digestion is accomplished by a particular type of cells — mobile mesodermal cells — that move around engulfing and dissolving food particles. While staring at mesodermal cells inside transparent starfish larvae, Metchnikoff, 37 at the time, had a thought. “It struck me that similar cells might serve in the defense of the organisms against intruders,” he wrote. He fetched a few rose thorns from the garden and stuck them into the larvae. If his hypothesis was correct, the larva’s body would recognize thorns as intruders and mesodermal cells would aggregate around the thorns in an attempt to gobble them up. As Metchnikoff expected, the mesodermal cells surrounded the thorns, proving his theory. He named his cells phagocytes, which in Greek means “devouring cells,” and likened them to an “army hurling itself upon the enemy.” [Continue reading…]