Etiology of Ulcerative Colitis

Abstract

Ulcerative colitis (UC) is a chronic immune-mediated inflammatory disorder of the colon, related to a complex contribution of environmental and host factors that increase the susceptibility of individuals. Genetics, environmental factors, dysbiosis, and dysregulated immune system: all these components together are necessary to trigger IBD. The temporal sequence of events leading to UC is unknown. UC is not a classically transmitted genetic affliction. The risk of developing the disease is increased in first-degree relatives but there is no evidence that it is related to genetics or environmental factors exposure early in childhood. The environmental factors associated with ulcerative colitis development are diet, smoking, breastfeeding, use of antibiotics or NSAIDs, urban location, pollution exposure, appendectomy, and hypoxia. In normal intestinal homeostasis environment, both innate and adaptive immune systems are integrated with various mediators and immune cells to maintain tolerance to commensal organisms. In UC patients, the innate immune system is responsible for inducing inflammatory reactions, while the adaptive immune system is crucial in the evolution of chronic inflammatory events. With the shifting global burden of ulcerative colitis, more research is needed to better understand the illness’s etiology in order to prevent and find potential novel therapeutic targets or predictors of disease burden in the future.