Early-life environment and risk of inflammatory bowel disease

Abstract

Inflammatory bowel disease (IBD) is an immune-mediated disease of the gastrointestinal tract. Due to the early-life maturation of the gut microbiome and immune system, infancy and toddlerhood are believed to be critical windows of risk for disease. However, prospective childhood data and the risk of IBD are scarce. The aim was to investigate the associations between early-life environmental factors and the risk of IBD. We used prospective data from two Scandinavian birth cohorts to investigate the association between childhood hygiene, diet, maternal infections, antibiotic use, and diet during pregnancy and the child’s risk of developing IBD. Our population consisted of 117,493 children followed from birth up to 16-21 years of age, of whom 451 (0.4%) developed IBD. Compared with no daycare attendance, attending daycare at age 36 months was inversely associated with the risk of Crohn’s disease. Having older siblings versus no siblings was associated with an increased IBD risk (Study I). One-year-olds with a high diet quality, fish and vegetable intake had a reduced risk of IBD (Study II), whereas those with any sugar-sweetened beverage intake at the same age had an increased risk of IBD. The timing of infections in early pregnancy and gastrointestinal infections in late pregnancy was associated with increased risk of IBD, particularly Crohn’s disease, in the child (Study III). In the Norwegian cohort, children born to mothers with high diet diversity during pregnancy had a lower risk of ulcerative colitis (Study IV). Our data suggest that the early-life environment, as early as during pregnancy and infancy, is associated with later IBD development. This underscores the potential importance of modifiable early-life risk factors for later disease risk and highlights the need for further research.