What Causes Crohn’s Disease?

If you search for an answer to what causes Crohn’s disease, you will find results that mostly say there is no known cause. However, studies from the last 10 years point to a variety of microbes as the culprits. Certain microbes are associated with Crohn’s disease. This information may lead to new treatments, which target those microbes. In addition, the information may also lead to preventative measures.

The cause of inflammatory bowel disease, especially Crohn’s disease, is thought to involve an inappropriate, persistent inflammatory response to commensal gut microbes in genetically susceptible individuals. This is an important element. Many microbial infections or imbalances can result in an inflammatory response.

Once Crohn’s disease has begun, an altered immune response causes gut inflammation and loss of tolerance to intestinal antigens. The loss of tolerance stimulates the T-helper cells to produce proinflammatory cytokines that cause considerable damage. It becomes a continuous cycle that damages healthy tissue. Still, the genetic component is crucial because, without the susceptibility, those individuals are unlikely to develop Crohn’s from the microbes.

Which microbes can trigger Crohn’s in a person with a genetic susceptibility? Scientists are just beginning to pinpoint the specific agents. For now, let’s look at three potential microbial triggers, a bacterium, a fungus, and a virus.

Mycobacterium avium subspecies paratuberculosis (MAP)

Mycobacterium avium subspecies paratuberculosis or MAP for short is a bacteria known for its ability to cause a disease in the stomach of cattle called Johne’s disease. Johne’s disease looks similar to Crohn’s disease, which is why scientists suspected the bacterium for Crohn’s. Some strains of MAP can survive pasteurization, which has prompted concerns that milk may be a frequent source of MAP.