Commensal bacterial glycosylation at the interface of host-bacteria interactions.

Commensal bacteria produce a diverse array of glycosylated molecules, including glycoproteins, glycolipids, peptidoglycan, capsular polysaccharides, and exopolysaccharides, which play fundamental roles in host-microbe interactions. Recent advances have highlighted the intricate mechanisms by which bacterial glycosylation contributes to immune regulation, epithelial barrier integrity, and microbial community stability, with implications for a range of conditions, including infectious diseases, chronic inflammatory disorders such as inflammatory bowel disease (IBD) and Alzheimer's disease, and metabolic diseases such as diet-induced obesity. This review provides a comprehensive synthesis of historical and recent insights into commensal bacterial glycosylation, emphasizing its role as a key mediator of host-bacteria interactions and its broader impact on gut homeostasis and systemic health.