In mice and humans, genetic variants seem to control the bacterial mix on and in bodies
BOSTON — Humans may be in charge of which bacteria live in and on them, researchers report. Scientists used to think that what people ate and where they lived were the main determinants of the microbes that colonize human bodies, but the new studies suggest the immune system selects its microbial companions. Paradoxically, that control may make it harder to change which microbes call a person’s body home.
Studies of mice and humans presented at the annual meeting of the American Society of Human Genetics indicate that the genetic makeup of the host determines which microbes set up shop in the intestines, on the skin and in other parts of the body. And a paper appearing October 29 in Genome Research finds that people with immune disorders host a wider variety of bacteria and fungi, some pathogenic, on their skin than do healthy people.
The set of microbes that live in and on a host organism — known as the microbiome — is highly individual,