The Scientist Who Drank Sour Milk to Save Lives - OZY | A Modern Media Company

The Scientist Who Drank Sour Milk to Save Lives

Ilya Metchnikoff at the Pasteur Institute in Paris.
SourceHarlingue/Roger Viollet via Getty

The Scientist Who Drank Sour Milk to Save Lives

By Joshua Eferighe


Because if you want something done right, sometimes you have to do it yourself.

By Joshua Eferighe

One of the worst things that could happen to you in the early 20th century was a stomachache. At the time, cramping, diarrhea, gas or anything having to do with the digestive tract was still a mystery to the medical world. While today the occasional upset stomach may sound benign, back then it could mean death. 

In England, Sir William Arbuthnot Lane endorsed and performed dozens of colectomies during the first two decades of the 20th century. Enemas were a major part of John Harvey Kellogg’s program at his sanatorium in Battle Creek, Michigan, where Kellogg treated the Roosevelts, Fords, Chryslers, Rockefellers and hundreds of other prominent individuals in the early 20th century. Some healthy patients died when surgeons removed their colons “to prolong life” or prescribed toxic medications to kill colon bacteria. And all because the medical world took the autointoxication theory promoted by Nobel Prize–winning Russian scientist Ilya Metchnikoff and ran with it.

According to Gabe Mirkin, a retired doctor and co-author of The Sports Medicine Book, because Metchnikoff’s theory of microbial balance proved our lower intestines to be a reservoir of harmful bacteria, doctors began treating the colon as public enemy No. 1. “People were unable to handle his knowledge, so the doctors did stupid, life-threatening things,” Mirkin says.

Today’s multibillion-dollar probiotics market shows how Metchnikoff was ahead of his time.

Not only did Metchnikoff have the knowledge but he also had status. Holding the deputy director position at the Pasteur Institute in Paris — the most prestigious position in medicine in the world — and having a Nobel Prize (for his work on how white blood cells kill pathogens) worked in his favor. But it wouldn’t be the only time that so-called experts and government officials jumped on an unproven theory in a crisis. (Paging Dr. Oz, Dr. Drew and President Trump.)

But Metchnikoff was no Trump or TV doctor. Born in Russia in 1845, the youngest of five children, he developed a love of experimentation and observing natural phenomena at an early age and gave science lectures to his older brothers and local children. By 11, Metchnikoff was enrolled at the Lycée Kharkov, where he first encountered microscopes and studied the microscopic structure of tissues. By 15, he had mastered German. In 1856, he attended the University of Kharkov to study natural sciences and completed the four-year program in two years. As for Metchnikoff’s residency in Paris, Mirkin says, “How could a Russian from Bulgaria come to Paris and have the Pasteur Institute? That’s never happened.”

The professor Elie Metchnikov (1845-1916), zoologi

Ilya Metchnikoff (center) inoculating a chimpanzee.

Source Viollet Collection/Getty

Metchnikoff’s theory of beneficial bacteria was not wrong; it was just explained incorrectly. He said that people could prolong their lives by eating fermented foods, but he didn’t specify that lactic acid–producing bacteria are what makes it possible. Scientists wouldn’t discover until later that “Bulgarian bacillus” (Lactobacillus bulgaricus) does not survive in the human gut, no matter how much is consumed, but a different bacteria does the trick.

Metchnikoff derived his theory while traveling through the Balkans with his second wife, Olga Belokopytova. He noted that the rural people of Bulgaria lived much longer than rich European city-dwellers. After digging deeper into their culture, he concluded that the secret to the low mortality rate of those who lived in the country was the good bacteria found in “soured milk,” which was a staple of their diet. By eating yogurt, which is loaded with lactobacilli, Metchnikoff postulated that people could replace harmful bacteria and prolong their lives. He was so convinced of this that he decided to consume fermented dairy products to test the theory on himself. As Olga later wrote in the Life of Elie Metchnikoff, “based on these considerations, he experimented on himself and systematically introduced in his diet sour milk, prepared with pure cultures of some lactobacilli. It had a beneficial effect on his health and we followed his example.”

His theory was widely rejected for nearly a century, but today’s multibillion-dollar probiotics market shows how Metchnikoff was ahead of his time.

He was willing to use himself as a frequent test subject. For example, he twice drank cholera-infected water during the 1892 cholera epidemic in France to test why the disease struck some but not others.

In 1916, shortly before his death, Metchnikoff instructed fellow Pasteur researcher Alexandre Salimbeni to “carefully” examine his intestines after he died. Up to his final moments, he was testing his theories on himself.

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