Antibiotic combination therapy for the induction and maintenance of remission in patients with ulcerative colitis

Dysbiosis of the gut microbiota has recently been identified as a therapeutic target for ulcerative colitis. We reported the effectiveness of antibiotic combination therapy (ATM therapy) for the induction and maintenance of ulcerative colitis remission. In this study, we aimed to investigate the long-term effectiveness of ATM therapy in a larger cohort. A prospective open-label trial was undertaken with 311 adult ulcerative colitis patients. The combination of oral amoxicillin 500 mg t.i.d., tetracycline 500 mg t.i.d. and metronidazole 250 mg t.i.d. was administered to patients daily for 2-4 weeks in addition to their conventional medication. Clinical assessments were performed using the partial Mayo score at baseline; at treatment completion; and at 3, 6, 9 and 12 months. Endoscopic evaluations were performed using the Mayo endoscopic score at baseline, 3 months, and 12 months. The compliance rate was 95.7%. The response and remission rates were 75.2% and 30.9% at completion, 62.7% and 29.6% at 3 months, 48.2% and 27.7% at 6 months, 37.9% and 24.4% at 9 months, and 35.4% and 24.4% at 12 months. The most frequent adverse events were diarrhea and fever. No life-threatening adverse events were observed during the trial. ATM therapy effectively led to long-term clinical response and remission in patients with active ulcerative colitis symptoms. However, further investigations are needed for the standardization of antibiotic therapy for ulcerative colitis in the future.