Introduction: 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. Methodology: 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.

Results: 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<0.00001). Patients with Ulcerative Colitis (UC), compared with controls, reported non-significant association with antibiotic exposure in childhood and any lifetime exposure. (OR 1.11 [0.93-1.33]; p = 0.25)

Conclusion: This meta-analysis suggests that exposure to antibiotics significantly increases the odds of developing CD and IBD. These findings re-emphasize the importance of cautious and judicious use of antibiotics.