Ulcerative Colitis (UC) is a chronic disease, in the progression of which an immune overreaction may play an important role. IL-22 is a member of the IL-10 superfamily of cytokines and is pleiotropic in immune regulation and inflammatory responses. IL-22 can produce protective effects, promote wound healing and tissue regeneration, while it can also induce inflammatory reactions when it is chronically overexpressed. Extensive literatures reported that IL-22 played an essential role in the pathogenic development of UC. IL-22 participates in the whole disease process of UC involving signaling pathways, gene expression regulation, and intestinal flora imbalance, making IL-22 a possible candidate for the treatment of UC. In this paper, the latest knowledge to further elucidate the role of IL-22 in UC was summarized and analyzed.

The intestinal barrier is a complex configuration that defends against external assaults and maintains intestinal health. Disruption of barrier function can lead to intestinal inflammation and various diseases. Mucins are the primary structural components of the intestinal barrier, and their extensive glycosylation is critical for their protective function. Mucin glycans enhance the physicochemical integrity of the mucus barrier, protect against enzymatic degradation, modulate host immune responses, and shape the gut microbiota by providing adhesion sites and selective nutrient sources. While proper glycosylation maintains barrier integrity, supports a balanced microbial ecosystem, and limits unnecessary immune activation, its disruption leads to compromised barrier function, microbial dysbiosis, increased intestinal permeability, and ultimately contributes to the development of chronic colitis and colorectal cancer. Therefore, mucin glycosylation plays a crucial role in preserving intestinal barrier integrity and preventing colonic diseases. This review summarizes the classifications and structural features of intestinal mucin glycosylation, elucidates their roles in maintaining barrier function and their pathological alterations in intestinal disorders, and highlights the implications of mucin glycosylation for precision diagnosis and targeted therapy of intestinal diseases.

Background: Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease. Intestinal barrier impairment represents a core pathogenic mechanism and a key therapeutic target for achieving mucosal healing and sustained remission. Methods: This narrative review summarizes intestinal barrier structure, disruption mechanisms, barrier-targeted therapies, and non-invasive monitoring approaches. A reproducible literature search was conducted in PubMed, Web of Science, and ClinicalTrials.gov from 2015 to 2026. Results: Barrier disruption in UC involves genetic susceptibility, proinflammatory cytokines, zonulin-mediated tight junction injury, gut microbiota dysbiosis, decreased short-chain fatty acids and secondary bile acids, impaired autophagy, and an abnormal mucin 2 (MUC2)-dependent mucus layer. Validated non-invasive monitoring tools include fecal calprotectin/lactoferrin, intestinal ultrasound, diffusion-weighted magnetic resonance imaging (MRI), and intravoxel incoherent motion (IVIM). Emerging therapies focus on tight junction stabilization, epithelial regeneration, autophagy regulation, MUC2 restoration, and microbiota modulation. Conclusions: Intestinal barrier dysfunction drives the initiation and progression of UC. Barrier-based monitoring and targeted repair strategies improve UC management. Future studies should develop personalized therapies, precise microbiota engineering, and multi-dimensional digital evaluation systems.

Ulcerative colitis (UC) is a chronic, relapsing-remitting subtype of inflammatory bowel disease (IBD), featured by continuous mucosal inflammation restricted to the colon and rectum. Although the exact pathogenesis of UC has not been fully clarified, intestinal barrier impairment and disrupted mucosal homeostasis are recognized as the central mechanism. Therefore, restoring intestinal mucosal barrier function represents a core strategy for UC prevention and treatment, which aligns with the therapeutic goal of achieving mucosal healing and sustained remission. In this review, we outline the composition and functional significance of the intestinal barrier, explore key mechanisms underlying its disruption, and summarize recent advances in UC-related monitoring strategies. Finally, we explore novel therapeutic approaches aimed at epithelial barrier repair. The review aims to provide insights valuable for both basic research and clinical management of UC.