Intestinal epithelial glycocalyx

The intestinal epithelial glycocalyx is a negatively charged (anionic), carbohydrate-rich layer comprised mainly of membrane-bound glycoproteins (mucins), proteoglycans, and glycolipids, located on the apical surface of intestinal epithelial cells. Its principal biological functions include serving as a diffusion barrier and initial defense against microbial pathogens and toxins, mediating cell–cell recognition and adhesion, and regulating the uptake and digestion of nutrients by concentrating digestive enzymes at the epithelial surface. The anionic character is derived from the numerous negatively charged sugar moieties, especially glycosaminoglycan chains (e.g., heparan sulfate, hyaluronic acid). This structure is also the primary site for adhesion of commensal bacteria and plays an essential role in forming the intestinal barrier and shaping the gut microbiota. Unlike classical drug targets such as receptors or enzymes, the glycocalyx is a dynamic supramolecular structure whose integrity and composition can be influenced by diet (e.g., oligosaccharides, prebiotics). Alterations or breakdown of the glycocalyx are implicated in increased susceptibility to infection and inflammatory disorders in the gut.

Other names

Glycocalyxintestinal glycocalyxbrush border glycocalyxepithelial glycocalyx

No classic mechanism; dietary/probiotic compounds may modulate structure, barrier, and microbiota interaction