Microscopic colitis-microbiome, barrier function and associated diseases.

Microscopic colitis (MC) is a chronic inflammatory bowel disease (IBD) with little in terms of endoscopic abnormalities and is frequently associated with other autoimmune diseases. The peak incidence of the disease is in middle aged or older populations, mostly females. The pathogenesis of MC is complex, multifactorial and poorly understood. Current concepts revolve around innate immunity or microbiome alterations as well as gut barrier dysfunction, all of which lead to the development of subtle inflammatory lesions in gut mucosa. The results of numerous basic and clinical studies involving molecular techniques as well as advanced endoscopic imaging revealed the important role of both intrinsic (e.g., hormonal) as well as extrinsic (e.g., NSAIDs and PPIs) factors in the modulation of gastrointestinal microbiome and MC pathogenesis. Capsule endoscopy as well confocal endomicroscopy imaging, alongside standard endoscopic techniques offer new tools in the evaluation of MC patients and allow their better stratification for novel treatment protocols based on modulation of gut microbiome and barrier function.