In many patients with Crohn’s disease, a condition that causes inflammation of the gastrointestinal tract, abdominal fat migrates to the wall of the small intestines, potentially creating scar tissue and blockage. What prompts the fat tissue to “creep” through the abdomen and wrap around the intestines has been a mystery.

Now, Cedars-Sinai investigators have found that the fat is actually responding to bacteria that have migrated out of damaged intestines directly into connective tissue. They believe the “creeping” fat migration attempts to plug leaks in the diseased organ and prevent the gut bacteria from getting into the bloodstream.

But what begins as a protective response apparently has no “off” switch. The presence of the fat may contribute to the development of severe intestinal scarring, or fibrosis, which occurs in 40% of Crohn’s patients. The data also led researchers to a specific microbe, Clostridium innocuum, which is responsible for prompting the fat to travel. This research could point the way to new therapeutics.