How a stomach bug infection may trigger Crohn's disease
Crohn's disease symptoms may be triggered by exposure to the norovirus in people who have certain genetic mutations, new research shows.
Scientists may have found a culprit for what can trigger Crohn’s disease.
In some people, exposure to the highly contagious norovirus might increase the risk of the bowel disorder, which causes the immune system to attack the digestive tract, research published Wednesday in Nature shows.
Scientists haven’t found exactly what causes the autoimmune disease, although it's been linked to people with certain genetic mutations. Earlier research pointed to one gene mutation that most people with Crohn’s share. However, nearly half of all Americans have this mutation, while only about half a million people in the U.S. have developed Crohn’s, suggesting that a genetic variant isn't the sole cause.
Using a mouse model and tissue from the human digestive tract, researchers at the NYU Grossman School of Medicine discovered that a common norovirus infection may play a role in the disease by blocking the production of a protein called apoptosis inhibitor five, or API5. That protein — which is released by certain T-cells — normally protects gut cells by telling the immune system to stop its attacks once a microbe has been defeated.
Norovirus is a highly contagious bug that causes diarrhea and vomiting. Up to 21 million people in the U.S. get sick with norovirus every year.Charles D. Humphrey / CDC“What we found is really interesting,” said study co-author Ken Cadwell, Recanati Family Professor of Microbiology at the NYU Grossman School of Medicine in New York. “In an unexpected way, T-cells protect the lining of the gut and infectious triggers interfere with that ability.”
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