纳米抗性淀粉结晶体调控结肠内环境的分子机制

项目名称： 纳米抗性淀粉结晶体调控结肠内环境的分子机制

项目编号： No.31471701

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 农业科学

项目作者： 周中凯

作者单位： 天津科技大学

项目金额： 76万元

中文摘要： 随着向结肠远端迁移，碳水化合物（C）的代谢强度减弱，生成短链脂肪酸特别是丁酸的浓度降低，而蛋白质（N）的代谢成为主导，产生毒性化合物(如硫化氢、亚硝胺等)，是诱导结肠病变的重要因素之一，虽然前述已获证实，但碳水化合物-蛋白质-肠道微生物间的相互作用机制尚未明确。我们发现抗性淀粉（RS）与菌群结构和代谢产物间有显著性构效关系，而该构效关系又是受RS的代谢动力学调控，这为筛选可向结肠特别是其远端输送可发酵型C源以改善结肠内环境提供了新思路。为了探讨结肠不同部位C/N的相对代谢强度与菌群结构间的内在联系，本课题以纳米RS结晶体为主要试验材料，采用体内外代谢模型研究该RS在不同代谢位点抑制N源代谢的能力，通过改善菌群结构及代谢产物的双重效应，从肠道菌群-肠道细胞-代谢产物三个层次研究该RS在结肠作用的分子机制。本课题的研究结果可针对结肠中因蛋白质的代谢对结肠环境所产生的负面作用提出有效的消减方案。

中文关键词： 碳水化合物；抗性淀粉；结构；代谢；分子机制

英文摘要： With the shifting towards the distal part of colon, the fermentation strength of carbohydrates decreases, leading to the reduction of short-chain fatty acids, in particular butyrate. However, the protein fermentation increases and produces a number of toxic compounds (eg. hydrogen sulfide, nitrosamines, etc.). These compounds are one of the key factors for causing colonic carcinogenesis. Although this relationship has been confirmed in previous studies，the interacting mechanism among carbohydrates, proteins and gut microbiota has not been fully understood. We found there is a relationship of structure-functionality among resistant starch (RS), microbiota structure and metabolites, and this relationship is regulated by RS fermentation kinetics in our previous studies. The results from our previous studies provide a new idea for screening fermentable carbohydrates, which could be delivered to the distal part of colon so as to improve the internal environment of the corresponding sites. In order to establish the relationship between the relative fermentation strength of carbohydrates and proteins and the microbiota structure at different sites of the colon, nanometer RS crystals are used for determining its fermentation property at different fermentation time via in vitro and in vivo models. Through the dual-effectiveness obtained from the improvement of microbiota structure and metabolites, a molecular mechanism will be investigated by the studies of gut microbiota, colonocytes and metabolites at three levels. The results from this project will provide an effective proposal for reducing the side-effects caused by the fermentation of proteins in the colon.

英文关键词： Carbohydrate;Resistant starch;Structure;Metabolism;Molecular mechanism