Supernatants were studied from patients with ulcerative colitis in remission for two reasons: Irritable bowel syndrome is considered as a mild form of inflammatory bowel disease; and patients with quiescence ulcerative colitis report irritable bowel syndrome like symptoms. Supernatants from these patients activate neurons.
Nerve activating properties of irritable bowel syndrome and ulcerative colitis supernatants were mainly due to proteases enzymes which are also signaling molecules. Nerve activation from irritable bowel syndrome supernatants was mediated by proteases signalling via protease activated receptor type 1, which played no role in effect of the ulcerative colitis supernatants.
An irritable bowel syndrome specific protein pattern, in particular an irritable bowel syndrome specific proteases profile has been found by the researchers. Proteome analysis revealed 204 differently expressed proteins in irritable bowel syndrome supernatants and 4 proteases which were only enhanced in irritable bowel syndrome supernatants. Protease inhibitor from probiotic Bifidobacterium longum strain blocked nerve activation triggered by irritable bowel syndrome supernatants. The interdisciplinary team over an 8 year period searched for putative biomarkers to identify organic changes in irritable bowel syndrome, and concluded that protease profiling holds promise as a strategy for identifying biomarkers of irritable bowel syndrome.
