为了揭示岩藻多糖（Fucoidan, FUC）的结构特点与肠道菌群的相互作用关系，该文制备了岩藻多糖的弱酸降解产物（Weak Acid Degradation Products of Fucoidan, AFUC）和氧化降解产物（Oxidative DegradationProducts of Fucoidan, OFUC）并通过人体粪便体外发酵模型研究了岩藻多糖及其降解产物对肠道菌群的调控作用。首先，FUC经降解得到的弱酸降解产物AFUC相对分子质量为7.4 kDa，硫酸基含量为3.12%，单糖组成为Fuc:Gal=24.83:75.22；而氧化降解产物OFUC相对分子质量降至19.6 kDa，研究发现低硫酸基含量的AFUC相比于FUC及OFUC更为显著的提高了发酵液中乙酸、丙酸、丁酸和戊酸的含量分别为提高了34.96%、135.41%、13.45%、16.92%，且异戊酸含量显著降低了24.55%，而FUC及OFUC两组间相比无显著差异。此外AFUC更为显著的促进拟杆菌门的富集（38.54%），降低厚壁菌门的相对丰度（17.71%），并更明显地抑制变形菌门的增殖（46.88%）。该研究表明岩藻多糖的硫酸基含量可能是影响其调节肠道菌群的一项重要因素。该文的研究结果为岩藻多糖在肠道健康领域的产品开发提供了参考依据。

To reveal the structural characteristics of fucoidan (FUC) and its interactions with the gut microbiota, weak acid degradation products (AFUC) and oxidative degradation products (OFUC) of fucoidan were prepared and the regulatory effects of fucoidan and its degradation products on gut microbiota were investigated through in vitro human fecal fermentation. The relative molecular mass of AFUC obtained from the degradation of FUC was determined to be 7.4 kDa, with a sulfate group content of 3.12% and a monosaccharide composition ratio of Fuc:Gal=24.83:75.22. The relative molecular mass of OFUC decreased to 19.6 kDa. Compared with FUC and OFUC, treatment using AFUC, which contains a low sulfate group content, significantly increased the contents of acetic acid, propionic acid, butyric acid, and valeric acid in the fermentation broth by 34.96%, 135.41%, 13.45%, and 16.92%, respectively, whereas it significantly decreased isovaleric acid content (24.55%), which was not affected by FUC and OFUC treatments. In addition, AFUC significantly promoted the enrichment of Bacteroidetes (38.54%), decreased the relative abundance of Firmicutes (17.71%), and considerably inhibited the proliferation of Proteobacteria (46.88%). This study suggests that fucoidan sulfate group content may play a crucial role in influencing regulatory effects on the gut microbiota. The results of this study serve as a valuable resource for fucoidanbased product development aimed at improving intestinal health.

辽宁省自然科学基金计划项目（2023-MS-278）