Fighting gut infections contributes to preventing Crohn’s disease and ulcerative colitis.

November 11, 2021

A research team from the Montreal Heart Institute (ICM) has shown that genes present in specific intestinal cells protect against the development of inflammatory bowel diseases (IBD). Published today in the scientific journal Genome Medicine, the study results show that more than a dozen of these genes, which contribute to the development of Crohn’s disease and ulcerative colitis, help fight viral and bacterial infections.

Crohn’s disease and ulcerative colitis, known as inflammatory bowel diseases, are characterized by chronic digestive system inflammation. The research team screened 145 genes associated with IBD risk in human digestive system cells, called intestinal epithelial cells and found that many of these genes are significant in helping these cells detect bacteria or viruses and set up the appropriate defensive response to control such infections. Thus, researchers have identified genes that make people more likely to develop chronic gut inflammation, characteristic of IBD when disrupted by genetic variants.

“Most of the current medical therapies used to treat Crohn’s disease and ulcerative colitis target the functions of immune system cells,” states Dr. John D. Rioux, MHI researcher, Full Professor of Medicine at the Université de Montréal and Canada Research Chair in Genetics and Genomic Medicine. “This study demonstrates the importance of developing therapeutic approaches aimed at strengthening the protective functions of the digestive system for the benefit of patients with inflammatory bowel disease.”

Inflammatory Bowel Disease

More than 270,000 people suffer from IBD in Canada and almost 10,000 new cases appear every year, resulting in annual economic costs of $2.6 billion. IBD is characterized by the body’s own immune system attacking parts of the digestive system. The exact causes of these diseases are still unknown, and there is currently no cure.

Previous genetic studies had already identified some differences in the genetic code associated with the development of IBD, but for most no actual disease-causing gene had not been found. “The challenge was how to use this genetic information to better understand the biological pathways leading to IBD,” said Jessy Carol Ntunzwenimana, doctoral student at the Rioux Lab and co-lead author of the study. Therefore, the research team had to develop a new approach to identify which genes are likely to be involved in IBD and reveal their biological functions.

“The findings from this study provide an important piece to the puzzle in understanding how the body’s interactions with the gut flora can predispose an individual to develop IBD,” stated Kate Lee, Vice President, Research and Patient Program at Crohn’s and Colitis Canada. “This is a great example of how genomic research can advance our understanding of health and disease, with a potential impact on patients who will be treated in the future,” stated Stéphanie Lord-Fontaine, Vice President, Scientific Affairs of Génome Québec. 

To view the complete study data, visit:  

Financial support of Génome Québec, Genome Canada, the Government of Canada, the Ministry of Higher Education, the Canadian Institutes of Health Research (with contributions from the Institute of Infection and Immunity, the Institute of Genetics, and the Institute of Nutrition, Metabolism and Diabetes), Genome BC, and Crohn’s and Colitis Canada made this study possible. This work was also supported by a grant from the National Institutes of Diabetes, Digestive and Kidney Diseases, Calcul Québec, Calcul Canada and the Canada Foundation for Innovation.