Environmental Exposure to Trace Elements and Heavy Metals Preceding the Clinical Onset of Inflammatory Bowel Disease

The immune dysregulation underlying inflammatory bowel disease (IBD) can start years before the diagnosis, but the role of triggering factors and environmental exposures during this period is still uncertain.

This single-center case-control study included asymptomatic subjects with an incidental diagnosis of IBD during the colorectal cancer screening program. Twenty-two minerals and 17 metals were determined at diagnosis in hair samples and compared 1:2 to healthy controls.

Six patients with preclinical IBD (3 ulcerative colitis, 67% left-sided; 3 Crohn's disease, 100% ileal, 67% inflammatory behavior) and 13 healthy non-IBD controls were included. No relevant occupational exposures were identified. We found statistically significant higher levels of sodium, potassium, and boron among cases compared to controls; while lower levels of zinc, uranium, copper, and germanium were observed.

A range of environmental exposures can be identified during the preclinical phase of IBD, but their relationship with the symptomatic onset and disease progression should be further explored.