Boston—One of the hallmarks of a healthy ecosystem is the presence of a diversity of organisms. This is true not only for tropical rain forests and coral reefs, but also for the complex ecosystem of the human intestinal tract, an environment populated by as many as 500 microbial species, many of which are nonpathogenic organisms that exist in symbiosis with their human hosts.
The observation that adding certain microorganisms to the diet can improve microbial functioning and benefit health has led to the concept of probiotic therapy. Such an approach is not new. As Sherwood Gorbach, MD, of Tufts University School of Medicine, pointed out at the World Congress on Pediatric Gastroenterology, Hepatology, and Nutrition in August, the scientific study of probiotics began with Russian microbiologist Elie Metchnikoff almost a century ago. And for thousands of years prior to Metchnikoff's work, people consumed yogurts and fermented milk for their health.
Friedrich MJ. A Bit of Culture for Children: Probiotics May Improve Health and Fight Disease. JAMA. 2000;284(11):1365-1366. doi:10.1001/jama.284.11.1365