To understand the underlying causes of inflammatory bowel disease (IBD), a team of Yale researchers focused on understanding how genetic markers that have been linked to IBD contribute to the disease process.

Led by associate professor of medicine Dr. Clara Abraham, the Yale team studied cells derived from the intestines and blood of healthy people. They stimulated the cells with bacteria or bacterial components, and observed immune responses in the context of a previously unknown gene associated with IBD named INAVA.

The researchers found that people who carried the genetic susceptibility in the INAVA gene had lower expression of the INAVA protein. That diminished the ability of immune cells to detect bacteria and produce a response that is critical to clearing bacteria. This inability to effectively clear bacteria can raise the risk of developing IBD.

The finding could help researchers better categorize IBD patients based on their genetic profiles. It also defines a pathway that could be a future target for treatment, said Abraham.

The paper was published in the Journal of Clinical Investigation.