Detection of enterohepatic and gastric Helicobacter species in fecal specimens of children with Crohn's disease

Background: Although there is compelling evidence to support the role of bacteria in Crohn's disease (CD), there is currently no solid evidence to support the role of any one specific bacterial causative agent. Recent studies have suggested that members of the Helicobacteraceae may play a role in the development of CD. The aim of this study was to further investigate the presence of members of the Helicobacteraceae in children with and without CD. Materials and methods: Fecal specimens from 29 children with CD, 11 healthy, normal controls, and 26 symptomatic controls with non-inflammatory bowel disease (IBD) pathology were obtained for DNA extraction and subjected to Helicobacteraceae-specific polymerase chain reaction (PCR). All PCR-positive samples were sequenced. The association between the presence of members of the Helicobacteraceae and each study group was statistically analysed using the Fisher's exact test. Results: Based on Helicobacteraceae-specific PCR analysis, 59% (17 of 29) of the children with CD were positive, which was significantly higher than that in asymptomatic healthy children [9% (1 of 11); p = .01] and that in symptomatic children with non-IBD pathology [0% (0/26); p < .0001]. Sequencing of the 16S rRNA gene of positive samples revealed the presence of both enterohepatic Helicobacter species and Helicobacter pylori in fecal specimens. Conclusions: For the first time, enterohepatic and gastric Helicobacter species have been identified in fecal specimens from children diagnosed with CD using PCR. Our data suggest that Helicobacter species may have a pathogenic role in the development of CD in a considerable proportion of children.