fermentation reveals an interplay relationship between oat β-glucan and human gut and their potential role in regulating gut cytokines.

Dietary oat β-glucan regulates the gut microbial composition and structure; however, the interplay relationship between oat β-glucan and the gut microbiota is unclear. In this study, we aim to investigate the interaction between oat β-glucan and human gut , a versatile carbohydrate utilizer, and explore the effect of their interaction on gut immunity homeostasis. The results of fermentation showed that oat β-glucan significantly increased the abundance of gut at the genus level. Then, strains were isolated from human gut microbiota and 9 strains of could grow on oat β-glucan and degrade oat β-glucan to reducing sugars. Notably, strains Bac02 and Bac08 possessed the strongest degradation capacity towards oat β-glucan. Genome analysis and functional annotations suggested that Bac02 and Bac08 contained abundant genes encoding glycoside hydrolases family 3 (GH3) and GH16, which might be responsible for β-glucan degradation. Moreover, cell experiments revealed that the metabolites from oat β-glucan fermentation by these 9 strains of could regulate the polarization of macrophages and maintain gut immunity homeostasis. Our study provides a novel insight into research on the interplay between dietary compounds and the gut microbiota.