Ulcerative colitis (UC) is a type of inflammatory bowel disease, that when combined with Crohn’s disease, affects more than 100 million people. Despite being this common, the cause for UC is uncertain. Dysbiosis of the gut microbiome has been considered as a prominent cause of inflammation, which likely plays a very important part in the pathogenesis of UC.

A study has found that samples taken from UC patients had a significant and constant decrease in Firmicutes bacteria, specifically Blautia, Clostridium, Coprococcus, and Roseburia. It was also confirmed that the reduction in these bacterial species actually had an important effect on those with UC. The reduction in Clostridium lowered how many short-chain fatty acids could be used, as well as lowering the utilization of butyric acid salt in intestinal cells. This induced inflammation, a major symptom of UC. Interestingly, UC patients living with healthy partners actually influenced the microbiota of their partners. This further shows the link the microbiome has to disease pathogenesis.

Chen, G.-L., Zhang, Y., Wang, W.-Y., Ji, X.-L., Meng, F., Xu, P.-S., … Bo, X.-C. (2017). Partners of patients with ulcerative colitis exhibit a biologically relevant dysbiosis in fecal microbial metacommunities. World Journal of Gastroenterology, 23(25), 4624–4631. https://www.wjgnet.com/1007-9327/full/v23/i25/4624.htm