Every human being serves as a home to thousands of different species of microbes. But scientists are now reporting that there are just three distinct microbial ecosystems in the guts of people they have studied.
The three "enterotypes" showed no particular link to ethnic background, sex, weight, health or age. One possibility is that the intestines of infants are simply randomly colonized by different pioneering species of microbes, which alter the gut so that only certain species can follow them.
The New York Times reports:
"Whatever the cause of the different enterotypes, they may end up having discrete effects on people's health. Gut microbes aid in food digestion and synthesize vitamins ... Enterotype 1 produces more enzymes for making vitamin B7 (also known as biotin), for example, and Enterotype 2 more enzymes for vitamin B1 (thiamine)."