Scientific Abstract

Proposal No. IBD-0298R
Principal Investigator:  Michael A. Kamm, MBBS, M.D.
Applicant Organization:  Australasian Gastro Intestinal Research Foundation, Ltd. (Melbourne, Australia) 
Project Title:  The gut microbiota in the East and West -- in the healthy population, inflammatory bowel disease patients, and relatives.  The ENIGMA (eastern inflammatory bowel disease gut microbiota) study
Period of Award:  July 1, 2010 - June 30, 2012

The incidence of inflammatory bowel disease (IBD) in Australia is equal to the highest in the world, in contrast to the incidence in Asia, which is low but rapidly increasing. The pathophysiology of IBD relates to the mucosal immune response to antigenic stimulation from the gut microbiota, on a background of genetic susceptibility. The children of immigrants from low to high incidence areas, but not the immigrants themselves, have a high incidence of IBD, suggesting that exposure to new environmental factors during childhood is a key factor in the development of IBD. “Westernization” of lifestyle and industrialization in Asia may also play a role.

Patients with IBD have altered gut microbiota. Little is known about the gut microbiota of IBD patients in Asia, and in particular whether it is changing to Western patterns, especially after migration. We aim to assess and compare the diversity of the microbiota within and between China and Australia (countries with different IBD incidence) both in the healthy and IBD populations, in subjects of Caucasian and Chinese ethnicity. Mucosal biopsies will be studied using state-of-the-art metagenomic techniques. Characterizing the microbiota in low but increasing, and high incidence countries and ethnic populations may allow for the identification of specific causal factors in the microbiota. The study will also assess serological responses to gut bacteria and genetic factors across countries.

This research aims to delineate the contribution of microbiota in a population of increasing risk. To our knowledge, this will be the first trans-national and trans-cultural study to examine the microbiota in this comparative way. Studying gut microbiota, genetics, and environmental factors in populations with changing incidence offers great hope of identifying potentially important etiological factors in IBD.