Xylo-oligosaccharide utilization by Weissella kandleri YT103: Transcriptomic analysis and intestinal barrier...

Xylo-oligosaccharides (XOS) are a promising prebiotic with strain-specific utilization by gut microbes. While Weissella spp. possess probiotic potential, the molecular mechanisms of XOS metabolism in W. kandleri remain unexplored, with multi-omics insights lacking for this species. Consequently, this study presents the first integrated genomic-transcriptomic analysis of XOS utilization in W. kandleri 103, identifying two gene clusters encoding key GH43 hydrolases (β-xylosidase and α-L-arabinofuranosidase) and MFS transporters. Results showed that XOS with a degree of polymerization of 4-6 significantly enhanced the growth kinetics of YT103 (μ = 0.310 ± 0.001 h^-1 vs. 0.238 ± 0.004 h^-1 on glucose) and acidification (final pH 4.66 ± 0.02). Transcriptomic analysis revealed that XOS significantly upregulated 13 key genes (e.g., xynB, mfs1), confirmed by qRT-PCR. XOS fermentation produced higher levels of short-chain fatty acids, particularly acetic acid (1857 μg/mL), demonstrating potent antibacterial activity against Escherichia coli and Staphylococcus aureus and enhanced intestinal barrier integrity in a Caco-2 model (29.26% TEER recovery vs. LPS control). These findings clarify the XOS metabolic pathways of YT103 and highlight its potential for synbiotic development targeting gut health enhancement.