In Nebraska, a colon-dwelling bacterium may trigger inflammatory bowel diseases by raising the immune system’s alarm against its peaceful bacterial community, reports a recent study led by the University of Nebraska-Lincoln. In the absence of its bacterial neighbors, the offending Helicobacter bilis bacterium caused only mild gut inflammation in mice. But adding a community of just eight other bacterial species into the mix — a typical human gut contains several hundred — was enough to stir up a more severe inflammatory response.
“Under normal conditions, the immune system tolerates gut bacteria,” said Ramer-Tait, Harold and Ester Edgerton Assistant Professor of Food Science and Technology. “But sometimes there are breaks in the intestinal barrier because of either a genetic susceptibility or an environmental trigger, which is similar to creating a hole in a fence. That breach then increases the likelihood that the immune system will launch an attack.”
Their findings suggest that many different bacteria native to the gut might draw the ire of the immune system, and ultimately contribute to inflammation.