Detection of intestinal bifidobacteria and lactobacilli in patients with Hirschsprung's disease associated enterocolitis

Background. The etiology of Hirschsprung's disease associated enterocolitis (HAEC) is unknown. Previous investigations have suggested that several factors such as dilation of proximal bowel, changes in colonic mucosal defence, and overgrowth of toxigenic bacteria may be related with it. This study was to quantify bifidobacteria and lactobacilli in the feces of Hirschsprung's disease (HD) patients with or without enterocolitis and those of normal children. Methods: Fresh stool specimens were collected at the first three days of the admission from 30 HD patients (aged 2 weeks to 2 years) and 15 healthy age-matched non-HD patients in the morning once a day for at least three days. All of them have not been given probiotics or antibiotics at least 7 days before stool collection. Hematoxylin-eosin and acetylcholinesterase histochemical staining on rectal biopsies of patients with HD confirmed the diagnosis of HD in all 30 patients. The 30 HD patients were divided into two groups based on the clinical history of enterocolitis: the HAEC group (n=10) and HD group (n=20). Fecal bifidobacteria and lactobacilli were consecutively quantified by SYBR Green I-based real-time PCR assay. Data were analyzed using SAS v. 12.6 for Windows. All tests were two-tailed, and P values <0.05 were considered statistically significant. Results: The mean levels of bifidobacteria were 7.35 +/- 0.59, 8.16 +/- 1.17, and 8.35 +/- 0.74 in the HAEC, HD and control groups, respectively. The bifidobacteria colonization levels were lower in the HAEC group than in the HD and control groups (P<0.05, P<0.001 respectively). The mean level of lactobacilli in the HAEC (5.51 +/- 0.65) and HD groups (5.87 +/- 0.78) was significantly lower than that in the control group (6.39 +/- 0.56) (P<0.05). But there was no difference in log numbers of lactobacilli between HAEC and HD groups (P>0.05). Conclusions: The scarcity of bifidobacteria and lactobacilli in HAEC patients may result in a decrease in epithelial barrier function and be a predisposing factor in the development of HAEC. This decline suggests that treatment with probiotics or prebiotics may be beneficial in these individuals. Further research will focus on whether probiotics can decrease the incidence of HAEC.