Too much antibiotic can decimate the normal intestinal microbiota, which may never recover its former diversity. That, in turn, renders the GI tract vulnerable to being colonized by pathogens. Now researchers from Memorial Sloan-Kettering Cancer Center, New York, NY, and Centro Superior de Investigaci-n en Salud P-blica, Valencia, Spain, show that reintroducing normal microbial diversity largely eliminated vancomycin-resistant enterococci (VRE) from the intestinal tracts of mice. The investigators showed further that the findings may apply to humans. The research is published in the March 2013 issue of the journal Infection and Immunity.
The reduced diversity of microbiota wrought by antibiotics "allow[s] VRE to invade and thrive in the intestine, suggesting that bacterial species that are wiped out by antibiotics are key to preventing colonization by VRE," says first author Carles Ubeda of the Centro Superior de Investigacion en Salud Publica, Valencia, Spain. "We hypothesized that repopulating the mice' intestines with the missing bacteria would promote clearance of the VRE."