Researchers at Sinai Health have developed a blood test capable of detecting the risk of Crohn’s disease years before symptoms appear, opening new opportunities for early intervention and prevention.
How the Test Works
The test measures the immune system’s response to flagellin, a protein found in certain gut bacteria. Studies led by Dr. Ken Croitoru at the Lunenfeld-Tanenbaum Research Institute revealed that individuals who later develop Crohn’s often show an unusually strong immune response to this protein long before any digestive symptoms arise.
Published in Clinical Gastroenterology and Hepatology, the findings highlight the crucial role of interactions between gut bacteria and the immune system in triggering the disease.
Rising Rates Among Children
Crohn’s is a chronic inflammatory condition of the digestive tract that can cause pain, fatigue, and digestive problems. In the past 30 years, Crohn’s rates among children have doubled, and globally, 6–8 million people live with the disease.
Early Detection and Prevention
Detecting antibodies against flagellin years before symptoms appear suggests that these immune responses may trigger Crohn’s rather than result from it. Dr. Croitoru emphasizes that understanding these early immune changes could help:
- Identify high-risk individuals
- Develop preventive measures
- Improve treatments, which currently achieve only partial responses in many patients
The GEM Project
The research is part of the Genetic, Environmental, and Microbial (GEM) Project, tracking over 5,000 healthy first-degree relatives of Crohn’s patients since 2008. The project collects genetic, biological, and environmental data to understand how the disease develops. So far, 130 participants developed Crohn’s, allowing researchers to study immune changes before symptom onset.
Abnormal Response to Beneficial Gut Bacteria
In healthy individuals, gut bacteria aid digestion and coexist peacefully with the immune system. In Crohn’s patients, however, the immune system reacts abnormally to normally beneficial bacteria. Collaborators from the University of Alabama, led by Dr. Charles Elson, developed a test that detects antibodies against flagellin, specifically from Lachnospiraceae bacteria, which are higher in Crohn’s patients.
Detection Years Before Symptoms
Monitoring 381 first-degree relatives of Crohn’s patients, researchers found that 28 participants with elevated antibodies later developed Crohn’s, with the strongest immune responses seen in siblings—suggesting a shared environmental influence. On average, the disease was diagnosed 2.5 years after antibodies were detected.
Toward a Preventive Vaccine
This discovery paves the way for developing a flagellin-based vaccine for high-risk individuals, potentially preventing Crohn’s disease before it develops.
