Xylooligosaccharide (XOS) has tremendous prebiotic potentials for gut health, but the relevant mechanisms are unclear. Herein, we confirmed the positive effects of dietary XOS enhancing gut barrier in a pig model via suppressing the expression of pro-inflammatory cytokines (IL-6 and IL-8). Meanwhile, XOS increased beneficial microbes Lactobacillus and decreased potential pathogenic bacteria. Moreover, XOS augmented microbiota-derived metabolites (mainly butyrate, propionate, and secondary bile acid) to strengthen the gut barrier and regulate gut immunity through activating host G-protein coupled receptors 109a or inhibiting histone deacetylases. Furthermore, XOS attenuated IgA-production and antigen cross-presentation processes. In addition, XOS supplementation led to the alteration of cell proliferation, remodeling of the energy metabolism, activation processes of serial genes or proteins, increased molecular chaperones, and the enhanced ubiquitin-proteasome pathway in cecal cells. Collectively, these results suggest that XOS enhances gut barrier and modulates gut immunity by optimizing gut microbiota and their metabolites, which is associated with alterations of biological processes.

低聚木糖 (XOS) 对肠道健康具有巨大的益生元潜力，但相关机制尚不清楚。在此，我们证实了日粮 XOS 通过抑制促炎细胞因子（IL-6和IL-8）的表达来增强猪模型中肠道屏障的积极作用。同时，XOS 增加了有益微生物乳酸杆菌并减少潜在的致病菌。此外，XOS 通过激活宿主 G 蛋白偶联受体 109a 或抑制组蛋白去乙酰化酶增强了微生物群衍生的代谢物（主要是丁酸盐、丙酸盐和次级胆汁酸）以增强肠道屏障和调节肠道免疫。此外，XOS 减弱了 IgA 的产生和抗原交叉呈递过程。此外，XOS 补充剂导致细胞增殖的改变、能量代谢的重塑、系列基因或蛋白质的激活过程、分子伴侣的增加以及盲肠细胞中泛素-蛋白酶体途径的增强。总的来说，这些结果表明 XOS 通过优化肠道微生物群及其代谢物来增强肠道屏障并调节肠道免疫力，这与生物过程的改变有关。