Crohn's disease

Nature 
Crohn's disease is an often severe gastrointestinal illness with symptoms such as abdominal pain, disabling diarrhoea, and loss of appetite. Drug treatments are limited and there is no cure.
Background 
Experts in Crohn's disease have long taken the position that the disease, whose cause is not clear, is set off by the body's immune system attacking itself, possibly due to a genetic factor. There has been accumulating evidence in recent years that the bacterium causing the cattle disease [Mycobacterium avium] subspecies paratuberculosis, or MAP, has some association with Crohn's disease and may play some role in its development. Those who claim a microbial trigger is important point to an immune reaction in some Crohn's patients to MAP and that up to 40 percent of Crohn's patients show signs of an antibody response to the MAP bacterium. Some doctors who have recorded signs of MAP in their patients and published their data, are already treating some successfully with antibiotics.
Incidence 
Up to 1 in 1000 people have Crohn's disease, and 1 in 750 have ulcerative colitis. Crohn's disease is prevalent in the USA, UK, Scandinavia and in Jews of Northern European origin. At least half million people are affected in the USA.
Claim 
1. The association of Crohn's GIT disease, for example, with psoriasis, arthropathies, sacroiliitis and ankylosing spondylitis suggests that increased uptake of food antigens may be a pathogenic mechanism of systemic inflammatory disease. The absorption of antigenic molecules that originate from food and/or gut microbes may initiate and then maintain inflammation in target organs.
Type 
(G) Very specific problems