Thousands of different bacterial species live within the human gut. Most are beneficial, while others can be harmful. A new study from an MIT-led team has revealed that these bacterial populations can remake themselves within the lifetime of their host, by passing genes back and forth. The researchers also showed that this kind of gene transfer occurs more frequently in the microbiomes of people living in industrialized societies, possibly in response to their specific diets and lifestyles. “One unexpected consequence of humans living in cities may be that we’ve created conditions that are very conducive to the bacteria that inhabit our guts exchanging genes with each other,” says Eric Alm, director of MIT’s Center for Microbiome Informatics and Therapeutics, a professor of biological engineering and of civil and environmental engineering at MIT, a member of the Broad Institute of MIT and Harvard, and the senior author of the new study.
