Effectiveness of adjunctive use of antibiotics in acute severe ulcerative colitis: a propensity score matching analysis

Background/Aims: The exact cause of ulcerative colitis (UC) remains unclear but likely involves an immune response to an unidentified component of gut microbiota. The use of antibiotics in treating acute severe UC (ASUC) remains controversial. This study aimed to assess the benefits of adding antibiotics to corticosteroids for managing ASUC. Methods: This retrospective study included patients with ASUC who met the Truelove and Witts diagnostic criteria at admission and received intravenous (IV) corticosteroids, with or without adjunctive antibiotics. Key outcomes included the need for medical and surgical rescue therapy during hospitalization and UC-related re-hospitalization rates at 1 week, 3 months, and 1 year. Propensity score matching (PSM) was employed to minimize selection bias in evaluating the impact of adjunctive antibiotics on clinical outcomes. Results: Of the 386 screened patients, 222 met the inclusion criteria: 75 (33.8%) received IV corticosteroids alone, while 147 (66.2%) received IV corticosteroids combined with antibiotics. After PSM (60 patients per group), the addition of antibiotics showed no significant effect on the need for medical rescue therapy during hospitalization, re-hospitalization, or clinical response based on the partial Mayo score after 1 week of hospitalization (68.3% vs. 60.0%; P= 0.341). Similarly, no significant differences were observed in the need for medical rescue therapy, re-hospitalization, or UC-related surgery rates at 3 months or 1 year (P> 0.05). Conclusions: In patients with ASUC, treatment outcomes did not significantly differ between those receiving IV corticosteroids alone and those receiving a combination of IV corticosteroids and antibiotics, suggesting that adjunctive antibiotic use may offer no added clinical benefits.