[关键词]
[摘要]
近年来,茶叶儿茶素调节肠道微生态的效果受到广泛关注。本研究通过大孔树脂柱层析分离纯化,制备得到纯度大于98%的茶叶儿茶素EGCG、EGCG3’’Me、ECG、ECG3’’Me。通过测定不同发酵时间点(0、6、12、24 h)体外培养中肠道菌群的变化以及短链脂肪酸的含量,评价茶叶儿茶素调节肠道微生态的作用。茶叶儿茶素在体外厌氧发酵24 h时,对于肠道有益细菌(双歧杆菌和乳酸菌)的增殖均起到了显著的促进作用(P<0.05),对于梭状菌和拟杆菌的增殖发挥了显著的抑制作用(P<0.05),对肠道总菌群数量影响不显著(P>0.05)。此外对于发酵过程中各种短链脂肪酸含量的变化进行了测定,发现添加儿茶素样品的培养基中,短链脂肪酸含量在各个发酵时间点都比对照组有显著提高(P<0.05)。实验同时对于茶叶儿茶素发酵过程中的代谢产物进行了结构鉴定。研究表明,包括甲基化儿茶素在内的儿茶素及其代谢产物,对于改善人体肠道环境、维护人体肠道平衡具有重要作用。
[Key word]
[Abstract]
Recently, tea catechins have been reported to have certain regulatory effect on intestinal microecology. In this study, high purity (>98%) of EGCG, EGCG3’’Me, ECG and ECG3’’Me were prepared from Guangdong Oolong tea by puri?cation procedures of macroporous resins. Then, the regulation effects of EGCG, EGCG3’’Me, ECG and ECG3’’Me on intestinal microecology in vitro were evaluated by monitoring the bacterial populations and analyzing the concentrations of short-chain fatty acids (SCFA) at different fermentation times (0, 6, 12 and 24 h). The results showed that tea catechins had significant proliferate effect (P<0.05) on beneficial bacteria (Bifidobacterium spp. and Lactobacillus/Enterococcus spp.), significant inhibitory effect (P<0.05) on Bacteroids-Prevotella group and Clostridium histolyticum group, while they did not affect the population of total bacteria (P>0.05). The total SCFA concentrations in cultures with tea catechins were significant higher (P<0.05) than that of the control in each fermentation time point. Moreover, the metabolites of tea catechins during the fermentation were also identified. Together, these results suggest that tea catechins, including methylated tea catechins have potential prebiotic-like activity by modulating intestinal microbiota and generating SCFA, contributing to the improvements of host health.
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[基金项目]
宁波市自然科学基金项目(2014A610189);宁波大学人才工程项目(zx2013000782);宁波大学校学科项目(xkl141055);宁波大学校级科研项目(XYL14026)