Probiotics for the prevention of Hirschsprung-associated enterocolitis: a systematic review and meta-analysis

Hirschsprung-associated enterocolitis (HAEC) is a life-threatening complication of Hirschsprung's disease. HAEC is reported to occur in 6-50% of patients preoperatively and in 2-35% postoperatively. The exact cause of HAEC is not fully understood, but disturbances of intestinal microbiota have recently been reported in patients with HAEC. In recent years, the administration of probiotics has been proposed to reduce the incidence of HAEC. We conducted a systematic review and meta-analysis to determine the effect of probiotics on postoperative HAEC. A systematic literature search for relevant articles was performed in four databases using the combinations of following terms "probiotics", "microbiota", "enterocolitis", "Lactobacillus", "Bifidobacterium", "Saccharomyces", "Streptococcus", and "Hirschsprung disease/Hirschsprung's disease" for studies published between 2002 and 2017. The relevant cohorts of the effect of probiotics in postoperative patients were systematically searched for clinical outcomes. Odds ratio (OR) or standard mean difference (SMD) with 95% confidence intervals (CI) were calculated using standardized statistical methodology. The search strategy identified 1274 reports. Overall, five studies met defined inclusion criteria, reporting a total of 198 patients. Two studies were prospective multicenter randomized control trials. Lactobacillus, Bifidobacterium, Streptococcus, and Enterococcus were used as probiotics. The incidence of HAEC with/without probiotics was 22.6 and 30.5%, respectively, but this was not statistically different (OR 0.72; 95% CI 0.37-1.39; P = 0.33). This study shows that the administration of probiotics was not associated with a significant reduction in the risk of HAEC. Additional studies are required to understand more fully the role of microbiota and complex interactions that cause HAEC. With increasing knowledge of the role of microbiota in HAEC, we are likely to understand better the potential benefits of probiotics in this disease.