Crohnâs disease (CD) is a growing health concern worldwide, accounting for significant human morbidity and mortality. Current
understanding of CD aetiology suggests that an infectious microbe(s) initiates a persistent and immune-mediated tissue injury in a
genetically susceptible host. CD is characterised by a relapsing and remitting disease course and involves segmental inflammation of the
gastrointestinal tract, commonly affecting the ileo-caecal region. There is strong evidence that microbial populations within the gut are linked
to CD for example, the presence of intestinal bacteria is essential for the development of colitis in several experimental animal models.
An elegant human study has shown that diversion of the faecal stream from the inflamed gut induced healing in CD, whereas re-infusion
of intestinal content into surgically excluded ileum triggered disease recurrence. There is ongoing debate about the precise mechanism by which a
microbe(s) might trigger CD. Two proposals include damage arising from changes in the global gut bacterial distribution, or from infection
with one or more candidate microbes. Studies over many years have described a possible link between CD and infection with a single
microbial candidate, for example Mycobacterium avium subspecies paratuberculosis (MAP).
Last date updated on July, 2014