Which mycobacterium is associated with Crohn's disease?

Mycobacterium paratuberculosis is thought to be associated with Crohn's disease due to its similarities with the bacteria known to cause Johne's disease in ruminants, which is a chronic inflammation of the intestine. Research has suggested a correlation between the presence of this bacterium in the intestines of individuals with Crohn's disease and the disease itself, leading to the hypothesis that M. paratuberculosis may play a role in the pathogenesis of Crohn's.

The connection lies in the fact that both M. paratuberculosis and the organisms responsible for causing Crohn's share structural and environmental characteristics, potentially leading to an inappropriate immune response in humans. While not definitively proven as the causative agent for Crohn's disease, its strong association with gastrointestinal manifestations and immune system interactions has made it a focal point in studies aiming to understand the etiology of this condition.

Other mycobacteria listed do not have a similar association with Crohn's disease. M. marinum is often linked to skin infections, M. avium is commonly associated with opportunistic infections in immunocompromised individuals, and M. gordonae is typically regarded as a non-pathogenic environmental organism.