A Home for the Microbiome

The human body is full of tiny microorganisms—hundreds to thousands of species of bacteria collectively called the microbiome, which are believed to contribute to a healthy existence. The gastrointestinal (GI) tract—and the colon in particular—is home to the largest concentration and highest diversity of bacterial species. But how do these organisms persist and thrive in a system that is constantly in flux due to foods and fluids moving through it? A team led by California Institute of Technology (Caltech) biologist Sarkis Mazmanian believes it has found the answer, at least in one common group of bacteria: a set of genes that promotes stable microbial colonization of the gut.