Department of Food Science & Biotechnology, Gachon University, Seongnam 13120, Republic of Korea.
Department of Functional Food and Biotechnology, Jeonju University, Jeonju 55069, Republic of Korea.
Carbohydr Polym. 2024 May 1;331:121898. doi: 10.1016/j.carbpol.2024.121898. Epub 2024 Feb 1.
Microbial exopolysaccharides (EPSs) are traditionally known as prebiotics that foster colon health by serving as microbiota nutrients, while remaining undigested in the small intestine. However, recent findings suggest that α-glucan structures in EPS, with their varied α-linkage types, can be hydrolyzed by mammalian α-glucosidases at differing rates. This study explores α-glucan-type EPSs, including dextran, alternan, and reuteran, assessing their digestive properties both in vitro and in vivo. Notably, while fungal amyloglucosidase - a common in vitro tool for carbohydrate digestibility analysis - shows limited efficacy in breaking down these structures, mammalian intestinal α-glucosidases can partially degrade them into glucose, albeit slowly. In vivo experiments with mice revealed that various EPSs elicited a significantly lower glycemic response (p < 0.05) than glucose, indicating their nature as carbohydrates that are digested slowly. This leads to the conclusion that different α-glucan-type EPSs may serve as ingredients that attenuate post-prandial glycemic responses. Furthermore, rather than serving as mere dietary fibers, they hold the potential for blood glucose regulation, offering new avenues for managing obesity, Type 2 diabetes, and other related-chronic diseases.
微生物胞外多糖（EPSs）传统上被称为益生菌，它们作为微生物群的营养物质促进结肠健康，同时在小肠中保持未消化。然而，最近的研究结果表明，EPS 中的α-葡聚糖结构具有不同的α-连接类型，可以被哺乳动物α-葡萄糖苷酶以不同的速率水解。本研究探讨了α-葡聚糖型 EPS，包括葡聚糖、交替糖和瑞特糖，评估了它们在体外和体内的消化特性。值得注意的是，虽然真菌淀粉酶（一种用于碳水化合物消化率分析的常用体外工具）在分解这些结构方面效果有限，但哺乳动物肠道α-葡萄糖苷酶可以部分将其降解为葡萄糖，尽管速度较慢。用小鼠进行的体内实验表明，与葡萄糖相比，各种 EPS 引起的血糖反应明显降低（p<0.05），表明它们是缓慢消化的碳水化合物。这得出结论，不同的α-葡聚糖型 EPS 可能作为成分减轻餐后血糖反应。此外，它们不仅作为膳食纤维，还有可能调节血糖，为肥胖、2 型糖尿病和其他相关慢性疾病的管理提供新的途径。
