Crohn’s disease is a form of inflammatory bowel disease for which the cause is currently unknown. Current estimates suggest several million cases of Crohn’s disease worldwide, with numbers growing in many countries. Given the similarities with TB, including chronic inflammation, clinical overlap and shared genetic susceptibility, our work aims to determine the potential role of Mycobacterium avium paratuberculosis in the development of Crohn’s with the view to opening up new treatment avenues.

Highlights of this work include:
 

  1. The absence of evidence of auto-immunity, reinforcing the importance of stating that we do not know the cause:
    a. Behr, Lancet, 2011
    b. Duffy & Behr, Chapter, 2020
  2. The demonstration that the first Crohn’s susceptibility gene mediates immune responses to a component of the mycobacterial cell wall
    a. Coulombe, JEM, 2009
    b. Hansen, JID, 2013
    c. Dube, PLoS Pathogens, 2023
  3. The development of a mouse intestinal infection model for the study of Mycobacterium avium paratuberculosis
    a. Duffy, Gut Pathogens, 2023
  4. The hypothesized direction of pathology from beneath the epithelial to the observed ulcers, akin to a volcano erupting through the crater
    a. Behr, Inflamm Bowel Dis., 2010
    b. Behr & Tonelli, JCC Plus ECCO, 2026

  5. The analysis of antibiotic trials, showing proof-of-concept, with important caveats and pending questions revised definition of zoonotic tuberculosis, with the demonstration of more virulent members of the Mycobacterium tuberculosis complex
    a. Behr & Hanley, Lancet ID, 2008
    b. Behr, Mehes & Bernstein, Gastroenterology, 2024

    Funding for our tuberculosis work has come from the following sources of support: Montreal General Hospital Foundation, McGill University Health Centre Foundation, Broad Foundation, Crohn's and Colitis Canada.

Paratuberculosis: organism, disease, control 2nd Edition Marcel A. Behr, Karen Stevenson, Vivek Kapur