Synbiotic delivery of arabinoxylan and a human-derived arabinoxylan-fermenting consortium influence mouse gut microbiome composition, metabolism, and resilience in sex-dependent ways.

Dietary fibers are generally considered to have strong impacts on governing ecological dynamics in gut microbial communities and metabolites. However, the extent to which the ecological modification capabilities of complex polysaccharides are enhanced by the presence of fermenting microbial specialists remains underexplored. Our prior study demonstrated that sorghum arabinoxylan (AX), a complex fiber with diverse glycosidic linkages, could offer unique ecological niches to sustain a stable consortium of organisms in vitro. In this study, the synergistic effect of AX and its specialist consortium was investigated using murine model and emphasized on their collective effects on gut microbiome modulation, specifically in improving the resilience after the exposure to antibiotics. We hypothesized that 1) continuous fiber intake aids in the engraftment of the specialist microbes to remodel the target host gut, and 2) the combined effect of fiber administration and the delivery of fiber-specific organisms has a pronounced ecological modulatory effect, especially in restoring a functional microbiome disrupted by antibiotic treatment. We found that while the cross-host consortium engraftment achieved modest success; the presence of specialist consortium-either independently or in combination with AX-facilitated swift shifts in fecal microbiota composition. In addition, the administration of AX and the fermenting consortium in antibiotic-treated groups resulted in a more rapid recovery of murine native microbiome over the fiber treatment alone, indicating that gut function recovery may be facilitated by transitory microbiota that perform ecosystem engineering roles. Overall, strategically pairing ecological niches (complex polysaccharides) with their corresponding specialist microbes offers a practical approach to effectively modify the gut ecosystem, thereby overcoming adverse conditions, enhancing stability and resilience.