Mouse small intestine villi stained for fucose-attached proteins. JOSEPH PICKARD, UNIVERSITY OF CHICAGOMice with systemic bacterial infections induce a pathway that makes a sugar called fucose readily available to feed the beneficial microbiota in the small intestine, according to a study published today (October 1) in Nature. This newly uncovered protective mechanism helps maintain the “good” bacterial populations in the gut while the animal is sick—and appears to protect against further infections.
“The most interesting aspect of this study is that the host is responding to a systemic microbial infection signal by altering glycans on intestinal epithelial cells, and this in turn increases host fitness in a microbiota-dependent manner,” said Laurie Comstock, a microbiologist at the Brigham and Women’s Hospital in Boston who wrote an editorial accompanying the study but was not involved in the work.
In the event of systemic bacterial infection, the host will try to neutralize or kill the harmful bacteria—known as a resistance response—and mitigate the negative impacts of the infection without directly targeting the pathogens—through what’s called a tolerance response. The innate immune system is known to mediate resistance mechanisms to these infections partly by releasing the cytokine IL-22 from innate lymphoid ...
