该研究比较了岩藻多糖（FUC）及其弱酸降解产物（AFUC）与氧化降解产物（OFUC）在BALB/c小鼠肠道内代谢情况及其对肠道代谢物的影响。通过高效液相色谱-二级质谱（HPLC-MS/MS）检测FUC、AFUC和OFUC随粪便排出体外的排出率分别为48.85%、40.78%和40.99%，发现岩藻多糖相对分子质量对排出率影响不显著，个体间差异较大。进一步对肠道细菌与FUC、AFUC和OFUC的在肠道内的代谢率做多元线性回归分析发现，Muribaculaceae菌科微生物是AFUC在肠道中代谢的主要参与菌，FUC和OFUC在肠道中代谢主要与毛螺菌科（Lachnospiraceae）、Muribaculaceae菌科和拟杆菌科（Bacteroidaceae）等相关。FUC、AFUC和OFUC在宿主体内通过影响肠道菌群代谢，共同影响了D-谷氨酰胺和D-谷氨酸代谢（D-Glutamine and D-Glutamate Metabolism）途径，降解产物OFUC和AFUC均显著影响生物素代谢（Biotin Metabolism）的代谢途径，说明岩藻多糖及其降解产物对肠道菌群相互作用的效果存在差异。本研究揭示了岩藻多糖通过肠道菌群发挥功效的机制，为岩藻多糖及其降解产物在食品领域的进一步应用提供数据支持。

The degrees to which the polysaccharide fucoidan (FUC) and its acid (AFUC) and oxidative degradation products (OFUC) are metabolized in the gut of BALB/c mice were investigated, and their effects on the gut metabolites were compared. High-performance liquid chromatography-tandem mass spectrometry measurement revealed the proportions of FUC, AFUC, and OFUC excreted in the mouse feces to be 48.85%, 40.78%, and 40.99%, respectively. Although the relative molecular mass of FUC did not have a significant effect on its excretion rate, there were large inter-individual differences. Furthermore, multiple linear regression analysis of the rates of FUC, AFUC, and OFUC metabolism in the gut revealed that AFUC was metabolized mainly by the Muribaculaceae, whereas FUC and OFUC were mainly utilized by the Lachnospiraceae, Muribaculaceae, and Bacteroidaceae. FUC, AFUC, and OFUC affected the metabolic activities of the gut microflora and jointly affected the D-glutamine and D-glutamate metabolic pathways in the host. OFUC and AFUC both significantly affected the pathway for biotin metabolism, indicating significant differences in gut microbiota interactions between FUC and its degradation products. This study reveals the mechanism by which FUC carries out its effects through the gut microbiota and provides data supporting further application of this polysaccharide and its degradation products in the food industry.

国家重点研发计划重点专项（2019YFD0902005）