Healthy first-degree relatives from multiplex families versus simplex families have a higher subclinical intestinal inflammation, a distinct fecal microbial signature, and harbor a higher risk of developing Crohn’s disease

Unaffected first-degree relatives (FDRs) from families with ≥2 affected FDRs with Crohn's disease (CD, multiplex families) have a high risk of developing CD, although the underlying mechanisms driving this risk are poorly understood. We aimed to identify differences in biomarkers between FDRs from multiplex vs simplex families and investigate the risk of future CD onset accounting for potential confounders.