枸杞子阿拉伯半乳聚糖调节肠道黏蛋白O-糖组的构效关系研究

Lycium barbarum fruit is firstly certificated as medicinal and edible resources by Ministry of Health, has been widely used as functional food and dietary supplement, and polysaccharides are one of the most important functional ingredients. Dietary polysaccharides are degraded by gut microbiota and promote the gut mucin O-glycosylation, which can protect the mucins structure, maintain the gut barrier integrity, and also regulate mucosal immune response and gut bacteria balance. At present, the studies mostly used crude polysaccharides as materials, and the structure analysis of mucin O-glycan was only based on the level of glycosyltransferase, which limit the structure-activity relationships study of polysaccharides and mucin O-glycan. In our previous study, we obtained Lycium brbarum fruit arabinogalactan, detailedly characterized its structure and evaluated the effect on mucins expression. Therefore, our project will investigate the effect of Lycium brbarum fruit arabinogalactan on the detailed structure and the expression of the gut mucin O-glycan by using the method of O-glycan released and simultaneous labeled and stable isotopes relative quantification based on bio-mass spectrometry and liquid-phase mass spectrometry. This study will reveal the structure-activity relationship of Lycium barbarum fruit polysaccharides regulating mucin O-glycan, lay a foundation for further study of the interaction mechanism between mucin O-glycan and intestinal bacteria, and provide a novel concept for the relationship between natural polysaccharides and intestinal health.

枸杞子是首批被国家卫生部列为药食同源的资源，被广泛用作功能性食品和膳食补充剂，多糖是其主要功能成分。膳食中多糖可被肠道菌群降解，促进肠道黏蛋白O-糖基化修饰，从而保护黏蛋白结构，维持肠道屏障完整，同时调节黏膜免疫反应和肠道菌群平衡。由于方法和手段的限制，现有研究多以粗多糖为材料，从糖基转移酶水平分析和推测黏蛋白O-糖链结构信息，制约了多糖与黏蛋白O-糖组的构效关系研究。本项目拟在前期对枸杞子阿拉伯半乳聚糖制备、精细结构解析及其对黏蛋白表达影响研究的基础上，运用课题组发展的O-糖链解离并同时标记及稳定同位素相对定量分析方法，以生物质谱、液相-质谱联用技术为手段，全面研究结构明确的枸杞子阿拉伯半乳聚糖对肠道黏蛋白O-糖链精细结构及表达量的影响，揭示枸杞子多糖调节黏蛋白O-糖组的构效关系，为深入研究黏蛋白O-糖组与肠道菌群相互作用机制奠定基础，为天然多糖与肠道健康关系研究提供新思路。

枸杞子是首批被国家卫生部列为药食同源的资源，多糖是其主要活性功能成分。研究表明膳食多糖主要是被肠道菌群降解，促进肠道黏蛋白O-糖基化修饰，从而维持肠道屏障完整，同时调节黏膜免疫反应和肠道菌群平衡，维持肠道健康。因此研究膳食多糖结构、肠道菌群和黏蛋白O-糖链间的关系具有重要意义。本项目完成了枸杞子阿拉伯半乳聚糖的制备和结构解析，健康小鼠和DSS诱导急性结肠炎小鼠的结肠黏蛋白O-糖链的解离释放，利用质谱分析获取黏蛋白O-糖链的表达图谱，利用在线PGC-LC-ESI-MS技术对小鼠结肠黏蛋白O-糖链的表达谱进行了分析，利用16S rRNA基因测序法获得小鼠菌群数据，揭示枸杞子多糖调节黏蛋白O-糖组的构效关系，从糖组学角度阐明了枸杞子多糖作为功能食品的作用机制。同时也完成了系统比价不同结构膳食多糖及复配多糖对健康小鼠的结肠黏蛋白O-糖链表达谱、肠道菌群结构的影响，初步阐明了结构膳食多糖结构、黏蛋白O-糖链表达及肠道菌群组成间的关系，为天然多糖与肠道健康关系研究提供了新思路。在本项目的支持下，在Carbohydrate Polymers、International Journal of Biological Macromolecules、Food &function、Food Chemistry、Journal of Food Measurement and Characterization、Critical Reviews in Food Science and Nutrition等期刊发表6篇SCI论文和1篇中文核心期刊论文。完成了1篇博士论文和1篇硕士论文。