不同成熟度桑椹多糖在体外粪菌发酵中的代谢特性

Metabolic characteristics of polysaccharides from mulberries at different maturity stages during in vitro fecal fermentation

[目的]研究不同成熟度桑椹多糖的体外酵解特性和肠道菌群调节作用。[方法]对桑椹青果、红果和紫果中的多糖进行体外粪菌发酵,测定体系的pH、短链脂肪酸和底物的变化情况,利用16S rDNA测序分析菌群结果。[结果]3种桑椹多糖均能被降解利用,并产生高含量的乙酸、丙酸和丁酸等代谢产物。而紫果和红果桑椹多糖的促短链脂肪酸生成能力强于青果。此外,它们还能选择性地调节肠道菌群,促进拟杆菌属(Bacteroides)、副拟杆菌属(Parabacteroides)、考拉杆菌属(Phascolarctobacterium)等的增殖,抑制梭杆菌属(Fusobacterium)等有害菌的生长。[结论]不同成熟度桑椹中的多糖均具有益生活性,可有效调节肠道菌群和产生有益代谢产物。其中,成熟度最高的紫果桑椹中的多糖效果最佳。

[Objective]This study investigated the in vitro fermentation characteristics and gut microbiota modulation effects of polysaccharides extracted from mulberries at different maturity stages.[Methods]Polysaccharides from green,red and purple mulberries were subjected to in vitro fermentation using human fecal microbiota.Changes in pH values,short-chain fatty acids(SCFA)levels and substrate composition were monitored.Gut microbiota composition was analyzed through 16S rDNA sequencing.[Results]Polysaccharides from all three mulberry types were effectively degraded and utilized during fermentation,generating significant levels of SCFAs,including acetic acid,propionic acid,and butyric acid.Purple and red mulberry polysaccharides demonstrated a superior capacity for SCFA production compared to those from green mulberries.Additionally,they selectively modulated gut microbiota,promoting the growth of beneficial bacteria such as Bacteroides,Parabacteroides,and Phascolarctobacterium,while suppressing harmful bacteria like Fusobacterium.[Conclusion]Polysaccharides derived from mulberries at three different maturity stages exhibit notable prebiotic activity by enhancing beneficial metabolic products and positively influencing gut microbiota composition.Fully ripe purple mulberries exhibited the most pronounced effects,suggesting their potential as a superior source of functional ingredients.