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 bifi dobacteria上海新华医院小儿外科沈涤华
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 fi rst three days of the admission from 30 HD
patients (aged 2 weeks to 2 years) and 15 healthy agematched
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 confi rmed 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 bifi dobacteria and
lactobacilli were consecutively quantifi ed by SYBR
Green I-based real-time PCR assay. Data were analyzed
using SAS v. 12.6 for Windows. All tests were twotailed,
and P values <0.05 were considered statistically
signifi cant.
Results: The mean levels of bifi dobacteria were
7.35±0.59, 8.16±1.17, and 8.35±0.74 in the HAEC, HD
and control groups, respectively. The bifi dobacteria
colonization levels were lower in the HAEC groupthan 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 signifi cantly
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 bifi dobacteria 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 benefi cial
in these individuals. Further research will focus on
whether probiotics can decrease the incidence of HAEC.
World J Pediatr 2009;5(3):201-205