And with more receptors in mice — and, presumably, people — on the Western diet, there are more places for the sepsis bacteria to infect. That's a simplification, but Rivera says identifying that receptor could give drug researchers a target for medicines that would reduce the threat of sepsis.

"Sepsis is responsible for more than 100,000 deaths annually in the U.S. alone," Rivera said. "And so, clearly, if we had a target for a drug therapy, it would greatly enhance our capabilities for the medical management of sepsis in these obese patients."

Chantal Rivera's study is published in the BioMed Central journal BMC Physiology.