Bacteroides intestinalis–Driven Arabinoxylan Fermentation Mitigates Inflammatory and Metabolic Dysfunction

Synergistic synbiotics, which pair defined microbial strains with their preferred carbohydrate substrates, offer a promising strategy to restore these functions. However, the rational design of such interventions remains challenging by insufficient understanding of microbial fiber-degrading capacities and the host-relevant bioactivities of fermentation-derived metabolites.

Here, we identify human colonic commensal Bacteroides intestinalis (B. intestinalis) as a key microbial mediator of dietary fiber-driven metabolic, immune, and neuronal benefits. We demonstrate that the synergistic interaction between B. intestinalis and its preferred substrate, insoluble wheat arabinoxylan abundant in dietary fiber, enhances the production of anti-inflammatory, antioxidant, and anti-diabetic phenolic compounds and bile acid species.