Antibiotic exposure and risk of new-onset inflammatory bowel disease: a systematic review and dose-response meta-analysis.

BACKGROUND AND AIMS: The association between antibiotic exposure and inflammatory bowel disease (IBD) remains controversial, especially whether there is a dose-response relationship. We aimed to conduct a systematic review and meta-analysis to thoroughly evaluate the risk of new-onset IBD associated with antibiotic exposure.

METHODS: Four databases were searched from their inception to September 30, 2023, for all relevant studies. The risk estimates were pooled together using random effects models, and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated, stratified by IBD subtype, age, exposure period, study type, and antibiotic classes. Dose-response relationship between the number of antibiotic prescriptions and IBD risk was assessed using generalized least squares regression analysis.

RESULTS: Twenty-eight studies involving 153,027 patients with IBD were included. Antibiotic exposure was significantly associated with an increased risk of new-onset IBD for prescription-based studies (pooled OR = 1.41, 95% CI 1.29-1.53) and for questionnaire-based studies (pooled OR = 1.35, 95% CI 1.08-1.68). This association existed for both Crohn's disease and ulcerative colitis, as well as in children and adults for prescription-based studies. The majority of antibiotic classes were associated with an increased IBD risk, with metronidazole (OR = 1.70, 95% CI 1.38-2.10) and quinolones (OR = 1.56, 95% CI 1.37-1.77) having relatively higher risk estimates. A positive nonlinear dose-response association was observed between the number of antibiotic prescriptions and IBD risk.

CONCLUSION: Antibiotic exposure was significantly associated with an increased risk of new-onset IBD, and a positive nonlinear dose-response relationship was observed. Antibiotic stewardship may be important for reducing IBD risk.