Intestinal mucin and epithelial surface glycans

The intestinal mucin and epithelial surface glycans represent the primary biochemical and physical barrier of the gastrointestinal tract, consisting of a complex network of secreted and membrane-bound glycoproteins (Pelaseyed et al., 2014, Immunological Reviews). The secreted mucus layer, dominated by the gel-forming mucin MUC2, prevents direct contact between the dense gut microbiota and the epithelial monolayer, while the underlying glycocalyx—composed of transmembrane mucins and glycolipids—provides a secondary defense and facilitates cell signaling (Hansson, 2012, Biology of the Cell). This system is a major therapeutic target in inflammatory bowel diseases (IBD), where barrier dysfunction is a hallmark of pathogenesis, and in drug delivery, where mucoadhesion is leveraged to improve the bioavailability of oral therapeutics (Varum et al., 2010, International Journal of Pharmaceutics). Pharmacological interventions include mucoprotective agents like sucralfate, mucin-secretagogues like rebamipide, and the development of glycan-mimetic decoys to prevent pathogen adhesion (Johansson et al., 2011, PNAS). Understanding the glycosylation patterns within this layer is crucial, as alterations in O-glycan structures are linked to both chronic inflammation and the progression of colorectal malignancies (Boltin et al., 2013, Journal of Clinical Gastroenterology). Furthermore, the mucus layer serves as a metabolic substrate for specific commensal bacteria, making its maintenance essential for a healthy microbiome-host relationship (Tailford et al., 2015, Nature Communications).

Other names

Intestinal mucus barrierGut glycocalyxMUC2-associated mucus layerGastrointestinal mucus glycoproteinsEnteric surface carbohydrates

Enhancement of the physical mucus barrier, induction of endogenous mucin synthesis, and utilization of mucoadhesive properties for localized drug delivery (Varum et al., 2010, International Journal of Pharmaceutics).