This study investigates the role of long-chain xylan (LCX) in promoting the growth of Bifidobacterium pseudocatenulatum in the human gut. Genomic and phenotypic analyses revealed that LCX-derived oligosaccharides are crucial for B. pseudocatenulatum growth, with strains possessing the BpXyn10A gene (likely acquired through horizontal gene transfer) exhibiting LCX utilization capabilities. Co-culturing experiments demonstrated that LCX-utilizing strains are more competitive. A dietary intervention study confirmed that LCX availability increases endogenous B. pseudocatenulatum levels, particularly when BpXyn10A is present. These findings highlight the importance of polysaccharide utilization for bifidobacterial adaptation and suggest the potential for manipulating the gut microbiota through dietary interventions.
