Meta-analysis: targeting the intestinal microbiota in prophylaxis for post-operative Crohn's disease

P>Background Enteric bacteria play an important early role in the pathogenesis of Crohn's disease. Aim To perform a meta-analysis of trials testing antibiotics or probiotics for prevention of post-operative recurrence of Crohn's disease. Methods Review of all randomized controlled trials comparing antibiotics or probiotics with placebo in prevention of endoscopic or clinical recurrence of Crohn's disease after surgical resection. Fixed-effect meta-analysis was performed with dichotomous data summarized using relative risk with 95% confidence intervals, where appropriate. Results Seven studies were identified as suitable for inclusion (two comparing antibiotics with placebo, five comparing probiotics with placebo). The use of nitroimidazole antibiotics (metronidazole, ornidazole) reduced the risk of clinical (RR 0.23; 95% CI 0.09-0.57, NNT = 4) and endoscopic (RR 0.44; 95% CI 0.26-0.74, NNT = 4) recurrence relative to placebo. However, these agents were associated with higher risk of adverse events (RR 2.39, 95% CI 1.5-3.7) and patient withdrawal. Probiotic administration was not associated with any significant difference in risk of recurrence compared with placebo. Conclusions Nitroimidazole antibiotics are effective in the prevention of post-operative Crohn's disease recurrence, but their side-effects limit acceptability. Probiotics have failed to show efficacy for post-operative prophylaxis, but may merit further study.