本文系Food Science and Human Wellness原创编译，欢迎分享，转载请授权。
流行病学研究也已经证实，肠道菌群的变化可能会对2型糖尿病（T2DM）的发病产生重大影响。有证据显示，2型糖尿病的拥有属性是肠道菌群的丰度和多样性降低。因此，通过调节肠道菌群逐渐成为一种预防和治疗T2DM的方法。而膳食干预是影响肠道菌群结构和功能的重要途径之一，为维持肠道菌群的稳态从而防治T2DM提供了可能。例如，有研究报道可溶性膳食纤维和四氢姜黄素可以通过促进厚壁菌门、乳杆菌门和普雷沃氏菌门的增殖，同时减少拟杆菌门、变形菌门、放线菌门和瘤胃球菌科的丰度，从而改善葡萄糖耐量和胰岛素敏感性。非消化性低聚糖（NDOs）由非α-1,4-糖苷键连接的单糖组成，不能被人体消化道降解而直接进入大肠，通过作为肠道益生菌增殖和产生短链脂肪酸（SCFAs）的能量来源来并抑制有害细菌的生长而发挥健康益处，包括抑制食欲、免疫调节、抗炎和降血糖。
在本研究中，广东省农业科学院蚕业与农产品加工研究所胡腾根博士、邹宇晓研究员等通过生物酶解桑叶多糖制备得到一种非消化性低聚糖（MLO 2-1），通过NMR分析对其结构进行了解析，并进一步通过体外粪菌发酵研究了其对T2DM肠道菌群的影响，通过LEFSe及Spearman分析MLO2-1可能特异性影响的肠道菌株，并通过动物实验验证了特异性菌株降血糖活性及其代谢利用MLO2-1的途径。
图2 体外消化实验结果
图3 NMR分析结果
图4 肠道菌群对MLO2-1的代谢途径
图6 MLO2-1和L. murinus降血糖活性
图7 L. murinus在以MLO2-1为唯一碳源的生长情况
胡腾根，男，工学博士，现为广东省农业科学院蚕业与农产品加工研究所助理研究员，主要研究方向为果蔬中活性物质互作及稳态化研究；多糖及低聚糖改善免疫力及调控糖脂代谢活性作用机制研究。目前主持广东省、广州市基金等项目6项，参与国家自然科学基金、广东省重点研发等多项项目，在国内外期刊公开发表学术论文60余篇，其中SCI收录40篇，第一、共一或通信作者论文16篇，授权国家发明专利6件。
邹宇晓，女，研究员，现为广东省农业科学院蚕业与农产品加工研究所副所长，主要研究方向为蚕桑资源和岭南特色果蔬的营养、生物活性物质及其功能评价的工作。先后主持国家和省部级以上相关课题10项；获各级成果奖9项，其中省部级科技进步一等奖4项、二等奖3项和三等奖2项；参编论著5部，发表论文300余篇。获国家授权发明专利70余件（第一发明人13件）。
Structural elucidation of mulberry leaf oligosaccharide and its selective promotion of gut microbiota to alleviate type 2 diabetes mellitus
Tenggen Hua,b,c, Yuanshan Yua,b, Jijun Wua, Yujuan Xua, Gengsheng Xiaod, Kejing Ana, Erna Lia, Sentai Liaoa, Yuxiao Zoua,*
a Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China
b Huagongliya (Foshan) Technology Industry Co., Ltd., Foshan 528313, China
c Heyuan Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Heyuan 517001, China
d Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
*Corresponding author.
Abstract
Two oligosaccharide fractions (MLO 2-1 and 2-2) were purified from enzymatic hydrolysate of mulberry leaf polysaccharide. The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide, which could be degraded by human digestive juice; while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota. Hence, MLO 2-1 was selected for the further analysis. The structure of MLO 2-1 was elucidated as follow: α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5)-α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1. The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota. Meanwhile, MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids, especially acetate and butyrate. The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated. Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus, a commensal bacterium presented a reduced level in T2DM mice. Animal experiments indicated that MLO 2-1 and L. murinus exhibited hypoglycemic activities. These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L. murinus.
HU T G, YU Y S, WU J J, et al. Structural elucidation of mulberry leaf oligosaccharide and its selective promotion of gut microbiota to alleviate type 2 diabetes mellitus[J]. Food Science and Human Wellness, 2024, 13(4): 2161-2173. DOI:10.26599/FSHW.2022.9250180.
或点击下方阅读原文查看文章
长按二维码关注我们！
