INTRODUCTION: IBD patients have a relapsing-remitting disease course, and amongst environmental factors that aggravate the disease course, common drugs aside from NSAIDs are not studied in detail. While the microbiome is considered to play a significant role on the disease course the impact of antibiotics is poorly understood. This study investigated the potential impact of different classes of antibiotics on course of disease in IBD using the Danish National Patient Registry.

METHODS: Danish IBD patients were studied using two nested case-control cohorts exploring associations between antibiotic types and IBD flare-ups, defined as IBD-related hospitalizations and/or high-dose systemic steroid exposure. Multivariate logistic regression and eXtreme Gradient Boosted decision tree (GBDT) machine learning methods evaluated antibiotic risks.

RESULTS: Two cohorts with 15,636 and 5,178 patients were analysed for risk of hospitalisation and course of steroids, respectively.The risk of a flare-up was significantly increased with antecedent exposure to quinolones (ATC:J01M. OR:3.04-3.82), antimycotics (ATC:J02A. OR:1.50-2.30), agents against amoebiasis and protozoal infections (ATC:P01A. OR: 1.95-3.18), intestinal anti-infectives (ATC:A07A. OR:2.09-2.32) and beta-lactam antibiotics (ATC:J01C. OR:1.36).The GBDT models achieved an AUC between 0.71-0.85 for predicting flare-ups, with the same above-mentioned antibiotics being in the 10 most important variables.

CONCLUSION: We found distinctive antibiotics to be significantly associated with an increased risk of IBD flare-ups. Our findings are corroborated by our GBDT machine learning models. Healthcare providers should be aware about the deleterious potential of specific antibiotic groups in patients with IBD only using these agents in a restrictive manner or preferentially consider alternative antibiotic groups.