Childhood exposure to a sibling with Crohn's disease alters gut microbiome and Crohn's disease susceptibility.

Childhood exposure to a sibling with Crohn's disease increases the risk of developing CD fourfold compared to adult exposure, driven by early-life microbiome changes.

• Why it matters: Understanding how early microbial disturbances influence Crohn's disease susceptibility can inform prevention strategies and improve risk prediction, addressing a key gap in disease etiology.
• What they did: The study analyzed data from the GEM Project and South Korean database, assessed gut microbiome alterations, and used germ-free mice to explore microbiota effects, developing a risk model based on fecal calprotectin and microbial enterotypes.
• The result: Childhood exposure was linked to reduced beneficial bacteria and heightened disease risk, with the risk model identifying high-risk siblings, enabling targeted early interventions to prevent Crohn's disease.