Structure and biological activities of glycoproteins and their metabolites in maintaining intestinal health

Glycoproteins formed by covalent links between oligosaccharide and polypeptides are abundant in various food sources. They are less sensitivity to gastrointestinal enzymes, and hence many of them undergo fermentation in the colon by microorganisms. Therefore, the confer various health benefits on the intestinal ecosystem. However, the current understanding of the effect of glycoproteins on intestinal microorganisms and gut health is limited. This is probably due to their heterogeneous structures and complex metabolic programming patterns. The structure and biological activities of glycoproteins and their microbial metabolites were summarized in this review. The metabolic pathways activated by intestinal bacteria were then discussed in relation to their potential benefits on gut health. Food-derived glycoproteins and their metabolites improve gut health by regulating the intestinal bacteria and improving intestinal barrier function, thereby amplifying immune response. The data reviewed here show that food-derived glycoproteins are promising candidates for preventing various gastrointestinal diseases. Further studies should explore the interaction mechanisms between intestinal microorganisms and host metabolites.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1987857 .