Lay Summary

Proposal No. IBD-0183
Principal Investigator:  Hazel M. Mitchell, Ph.D.
Applicant Organization:  The University of New South Wales (Australia)
Project Title:   Investigation of the role of members of the Helicobacteriaceae in Crohn’s disease
Period of Award:  September 7, 2006 – March 6, 2008

Recent studies show that a group of bacteria, the lower bowel Helicobacter species, which naturally live in the mucus on the surface of the bowel wall of a number of mammals, can lead to an IBD-like condition in both mice and primates.

We conducted a preliminary study in two groups of children, the first presenting for colonoscopy and the second a group of normal children with no symptoms, to determine if these bacteria were present in their large bowel and if so, where they were located. This study showed that 100% of children with IBD and IBS were positive for Helicobacteriaceae bacteria as compared with and only 1/14 control. These results indicated to us that members of this family are commonly present in the mucus layer covering the large bowel of children with CD.

The aim of our current research proposal is to investigate the role of bacteria belonging to the Helicobacteriaceae family, in the initiation and/or continuation of the inflammation associated with CD. We have chosen to conduct our studies in children as they are in the early stages of disease and relatively free of significant confounding factors that make such studies in adults more difficult. The specific goals of this study are to:

• Collect intestinal lining and fecal samples from children undergoing colonoscopy and diagnosed with CD at hospitals in three different centers in Australia, Canada and USA.
• Collect stool samples from well children with no bowel problems (of the same age and ethnicity as CD children) attending each of the three locations.
• Detect, using molecular techniques, the presence of members of the Helicobacteriaceae in colonic samples and/or stools from these children and where present identity the species involved.
• In those CD children shown to be positive for members of the Helicobacteriaceae, to culture and where successful, identify and characterize, the species involved.
• Assess, in children with CD, the location (if present) of these bacteria using special techniques.
• Determine if an association exists between all members, or a subset of species, from the Helicobacteriaceae family and CD.

If these bacteria are linked with CD, it is likely that this will lead to significant benefits to patients with CD. Firstly, special tests could be developed to rapidly identify these bacteria, thus allowing rapid diagnosis and to allow for screening for these bacteria in family members of other persons suspected at being at risk of developing IBD. Secondly, and of particular significance to those with CD, these bacteria could be eliminated using antibiotics. Thirdly, successful growth of these bacteria will let us do studies to work out how they cause disease.