Review finds antibiotics associated with heightened risk of inflammatory bowel disease

There was a positive, nonlinear dose-response association between the number of antibiotic prescriptions patients received and their inflammatory bowel disease risk, according to a systematic review.

Antibiotic exposure is linked with an increased risk of new-onset inflammatory bowel disease (IBD), according to results of a recent systematic review and meta-analysis.

A total of 28 studies including 153,027 patients with IBD were included. Seventeen studies used prescription data, assessing antibiotic exposure in the first year of life or within two to five years before IBD diagnosis. Eleven studies were based on questionnaires and most often defined antibiotic exposure as exposure at least four times annually during certain periods of childhood. All studies were published between 2004 and 2023. Findings were published by Clinical Gastroenterology and Hepatology on Feb. 27.

Antibiotic exposure was significantly associated with an increased risk of new-onset IBD in prescription-based studies (pooled odds ratio [OR], 1.41; 95% CI, 1.29 to 1.53). An association was also seen in questionnaire-based studies (pooled OR, 1.35; 95% CI, 1.08 to 1.68). In prescription-based studies, the association was observed with both Crohn's disease and ulcerative colitis. Although the majority of antibiotic classes were linked with an increased IBD risk, metronidazole (OR, 1.70; 95% CI, 1.38 to 2.10) and quinolones (OR, 1.56; 95% CI, 1.37 to 1.77) had relatively higher risk estimates. Data also showed a positive nonlinear dose-response association between the number of antibiotic prescriptions and risk of IBD.

To the authors' knowledge, the study is the most recent and comprehensive meta-analysis on antibiotic exposure and new-onset IBD. The association was more robust and consistent across prescription-based studies, they noted.

"If antibiotic exposure can be identified as an environmental trigger for IBD, this will have important implications for the management and prevention of IBD. Strengthening antibiotic stewardship by strictly adhering to prescription guidelines is extremely important in general, and we now show this has relevance in the prevention of IBD as well," the researchers said.

One limitation to the primary analysis was high statistical heterogeneity, which may have been due to confounding. Because antibiotic prescriptions may not reflect actual use, the results should be interpreted with caution.

"Further studies on the mechanisms related to the effect of antibiotic–microbiota interactions on IBD development are warranted," the authors concluded.