玉竹多糖的体外消化特性及其与乳杆菌和大肠杆菌的相互作用

In vitro Digestion Characteristics of Polygonatum odoratum Polysaccharides and Their Interaction with Lactobacillus bulgaricus and Escherichia coli

采用水提醇沉法制备玉竹多糖,对其理化性质进行测定;利用体外模拟消化模型研究玉竹多糖在体外模拟唾液、胃和胃肠道中的消化情况;进一步考察其与乳杆菌(植物乳杆菌,CGMCC NO.1258)和大肠杆菌(大肠埃希氏菌,CGMCC NO.1.1521)的相互作用。结果表明,玉竹多糖本身不含还原糖,水解后主要由甘露糖、半乳糖醛酸、葡萄糖、半乳糖组成,含有2种分子质量分布,分别为1.37×10^(6)、6.75×10^(3)Da;玉竹多糖在被模拟唾液、胃液、胃肠液消化后,还原糖、单糖组成、分子质量均无明显变化,说明玉竹多糖在体外模拟消化系统不能被分解;但在乳杆菌和大肠杆菌的作用下,玉竹多糖发生了不同程度的降解,且玉竹多糖对乳杆菌的生长起到促进作用,对大肠杆菌的生长起到抑制作用。

Polygonatum odoratum polysaccharides were prepared by water extraction and alcohol precipitation method and their physical and chemical properties were determined. In vitro simulated digestion model was used to study the digestion of P. odoratum polysaccharides in simulated saliva,stomach and gastrointestinal tract,and their interaction with Lactobacillus bulgaricus(CGMCC NO.1258) and Escherichia coli(CGMCC NO.1.1521)was further investigated. The results showed that the polysaccharides themselves did not contain reducing sugars,and were mainly composed of mannose,galacturonic acid,glucose and galactose after hydrolysis,with two molecular weight distributions of 1.37×10~6 Da and 6.75×10~3 Da. After being digested by simulated saliva,gastric juice and gastrointestinal juice,the composition of reducing sugars,monosaccharides and molecular weight did not change significantly,indicating that the polysaccharides could not be decomposed in the simulated digestive system in vitro. However,under the action of L. bulgaricus and E. coli,P. odoratum polysaccharides were degraded in different degrees,and the polysaccharides promoted the growth of L. bulgaricus and inhibited the growth of E. coli.