Gut: Immune System Signals of Bowel Disease Can Appear 10 Years Before Diagnosis

Inflammatory bowel disease includes Crohn’s disease and ulcerative colitis. These conditions involve chronic inflammation of the digestive tract and can cause abdominal pain, diarrhea, and fatigue. The diseases are usually detected after symptoms appear, by which time intestinal tissue may already have been damaged.

The researchers analyzed 2,000 blood samples collected from 500 US military personnel. Crohn’s disease subsequently developed in 200 participants, while another 200 developed ulcerative colitis. The remaining participants did not develop either condition. The scientists looked for antibodies targeting various proteins from bacteria, viruses, food, and the body’s own tissues.

People who were later diagnosed with Crohn’s disease were more likely to have antibodies against the Epstein–Barr virus. These differences were detectable as early as ten years before diagnosis. The strongest signal was observed in participants who subsequently developed severe disease with complications, including intestinal strictures.

In participants who developed ulcerative colitis, the researchers identified a different pattern of immune response, including antibodies against one of the body’s own proteins.

“Changes in immune system activity may begin long before the first symptoms appear. In the future, antibody testing could help identify people at increased risk of developing the disease and pave the way for early diagnostic and preventive approaches,” the scientists noted.

The test is not yet ready for routine clinical use. The findings need to be confirmed in other populations. In addition, the study identifies an association between immune changes and the subsequent development of the disease, but does not prove that viral infections directly cause inflammatory bowel disease.