Microbes in your stomach support the multi-billion-dollar probiotics industry, your workout, and possibly even your sex drive.
Probiotics are back (yes, they were once a thing) and a growing number of companies claim that by adding live microorganisms, bacteria does the body good. Dannon’s Activia yogurt touts probiotics as a way to regulate the digestive system. Powerful Yogurt and Naked Pizza serve up similar health claims. The brisk business in beneficial bacteria brings in around $28 billion a year. With names like Lactobaccili, Streptococci, and Bifidobacteria, these microorganisms have been linked to lower rates of constipation, ulcerative colitis, and chronic diarrhea. Consult with Dr. Google and you might find that probiotics are the next Prozac, the cure for acne, and a surefire boost to your sex appeal.
Despite nearly a century of research—first on “scientifically soured milk” and life-prolonging yogurts—the concept remains largely under-researched and oversold. At the same time, scientists are finding that the trillions of microorganisms, as many as 10,000 different species, or about 160 species per person, flourish in our warm, wet intestines. Microbes influence our health, sometimes far beyond the gut itself. If the human microbiota, as it’s known, is an integral part of overall health and physical fitness, could microbes serve as performance-enhancing microorganisms?
One study—known, in some circles, as the “Great Balls of Fire”—claimed that probiotic yogurt imbued male mice with bigger balls and a behavior the researchers called swagger. The lead investigator, Susan Erdman, a cancer biologist at MIT in Cambridge, Mass, is a researcher with an unflagging enthusiasm for her work (and also a dedicated athlete). Three years ago, quite by chance, she told me, a colleague had noticed that the female mice in her lab colony were becoming so unbelievably shiny. . .