Trillions of bacteria live inside your bowels, outnumbering your own cells 10 to 1. These microbial communities contain thousands of species that vary from person to person. But according to a new study, they divide into just three basic groups, dubbed enterotypes. Everyone has one of four blood types; apparently we have one of three gut-microbe types, too.
Computational biologist Peer Bork from the European Molecular Biology Laboratory in Heidelberg, Germany, discovered the enterotypes by sequencing bacterial DNA in stool from Japanese, European, and American volunteers. The sequences clustered into three groups that did not follow patterns of age, gender, body weight, or nationality. “It was a surprise to us,” Bork says.
The membership of each community might be influenced by blood groups or our immune systems. Whatever their origins, enterotypes may affect your health by determining how well you break down food or how susceptible you are to certain diseases. “Eventually doctors will be able to prescribe different drugs or diets according to a patient’s enterotype,” Bork says. “I think we’ll find each group’s needs are different.”