McMaster University

McMaster University

Faculty of
Health Sciences

A decade of Walkerton research leads to breakthrough

Published: January 27, 2010
Stephen Collins
Stephen Collins, professor of medicine and Associate Dean for Research, Faculty of Health Sciences
John K. Marshall
John K. Marshall, associate professor of medicine and head of clinical research for the Division of Gastroenterology

Studies of people who became ill following the tainted water tragedy in Walkerton, Ont., have led to a research breakthrough in the underlying causes of a bowel disorder that appears following an infection.

A team of investigators, including those from the Farncombe Family Digestive Health Research Institute at McMaster University, has discovered variations in the DNA of a person’s genes can increase the risk of developing post-infectious irritable bowel syndrome (PI-IBS), a common ailment among the victims of the Walkerton tragedy.

The details of the study will be published in the journal Gastroenterology this spring.

Post-infectious irritable bowel syndrome is a functional bowel disorder that has an acute onset after an episode of gastroenteritis, or inflammation of gastrointestinal tract.

"These patients suffer from chronic abdominal pain, discomfort, bloating and disturbed defecation in the absence of any detectable structural or biochemical abnormalities," said John Marshall, a gastroenterologist and an associate professor of medicine in the Michael G. DeGroote School of Medicine at McMaster University.

"After the exclusion of known organic disorders, like Crohn’s disease and ulcerative colitis, such patients are diagnosed with PI-IBS."

Marshall, a member of the Farncombe Institute and head of clinical research for the Division of Gastroenterology in the Michael G. DeGroote School of Medicine, was the co-principal investigator of the study, along with Denis Franchimont, formerly of McGill University and now of the Erasme Hospital in Brussels, Belgium.

Stephen Collins, a professor of medicine in the Michael G. DeGroote School of Medicine and a founding leader of McMaster’s digestive research program (now the Farncombe Family Digestive Health Research Institute), also collaborated.

"Although the exact cause of PI-IBS remains unknown, we now know for the first time that, in addition to the environmental trigger, genetic factors are also playing a critical role in the development of this disease," said McGill University PhD candidate Alexandra-Chloé Villani, who led the research team under the direction of the principal investigators.

Almost 10 years ago, the municipal water supply of Walkerton was contaminated with E. coli and Campylobacter jejuni, leading to one of the worst public health crises in Canadian history. Seven people died and 2,300 suffered symptoms, including bloody diarrhea. Of those who became ill, 36 per cent developed PI-IBS, giving the town the highest incidence of PI-IBS ever reported.

"The biological implications of the identified genetic risk factors emphasize the important roles of the gut microbial flora, intestinal barrier function and inflammatory pathways in contributing to the onset of PI-IBS," Villani said.

Though these results will not lead to any new short-term treatments for PI-IBS, Marshall is confident that in the longer term the research will lead to better patient care, including potentially novel therapeutic targets for research, as well as improved medical decision-making concerning victims of future outbreaks.

The study was supported by the Crohn’s & Colitis Foundation of Canada (CCFC) and the Ontario Ministry of Health and Long-Term Care.

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