The association of antibiotic exposure with new-onset inflammatory bowel disease: A systematic review and meta-analysis

•Childhood exposure or any lifetime exposure of antibiotics increases risk of inflammatory bowel disease and more specifically Chron's disease.•Childhood exposure to antibiotics is associated with childhood-onset CD.•There is no relation between childhood exposure to antibiotics and childhood-onset UC or adult-onset UC. The role of antibiotics in the development of inflammatory bowel disease (IBD) remains controversial, primarily due to conflicting data from individual studies. We conduct a systematic review and meta-analysis to study the effect of antibiotic exposure on IBD development. The MEDLINE and Cochrane CENTRAL databases were queried from their inception to April 2021 for published articles studying the association between antibiotic exposure and new-onset IBD. Our analysis was stratified by timing of antibiotic exposure – exposure in childhood and any lifetime exposure. Adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) from each study were pooled using a random-effects model. 10 case-control studies and 2 cohort studies (N = 29,880 IBD patients and N = 715,548 controls) were included. Patients with Crohn's Disease (CD), compared with controls, were associated significantly with antibiotic exposure in childhood and any lifetime exposure to antibiotics (OR 1.52 [1.23–1.87]; p