膳食单宁酸影响肠道菌群调控糖脂代谢的效应及机制研究

Dietary tannic acid is an important functional factor widely distributed in various foods, which attenuates hyperglycemia and hyperlipidemia in the practical application. It can selectively inhibit the growth of harmful bacteria, promote the proliferation of beneficial bacteria, and finally affect the intestinal microecology. Studies have shown that changes in intestinal microecology and its metabolites short-chain fatty acids (SCFAs), have important effects on glycolipid metabolism. In addition, the metabolites of dietary polyphenols also play an important role in glycolipid metabolism. Previously, we used a low dosage of dietary tannic acid (100mg/kg/day) to intervene the obese mice, and preliminarily proved the effect of dietary tannic acid on gut microbiota and glycolipid metabolism. Based on previous reports and our preliminary research data, this study raises the following scientific questions: 1) How does dietary tannic acid modulate the intestinal microecology? 2) Does dietary tannic acid regulate the glucolipid metabolism by modulating gut microbiota and its metabolites? 3)Does dietary tannic acid regulate glycolipid metabolism signaling pathways through gut microbiota metabolites? The purpose of this study is to clarify the effect and mechanism of dietary tannic acid on regulation of glucolipid metabolism by gut microbiota, and provide the latest theoretical basis for the effective utilization of dietary tannic acid.

膳食单宁酸是广泛分布于各种食物的重要功能因子，在实际应用中具有降糖降脂的功效。它能够选择性的抑制致病菌的生长，促进肠道中有益菌的增殖，最终影响肠道微生态。研究表明，肠道微生态及其代谢产物短链脂肪酸SCFAs的变化会对糖脂代谢产生重要的影响。此外，膳食多酚的代谢产物在糖脂代谢中也起着非常重要的作用。前期我们利用低剂量膳食单宁酸（100mg/kg/day）干预肥胖小鼠，初步证明了低剂量膳食单宁酸对肥胖小鼠肠道菌群和糖脂代谢的影响。根据以往报道和前期研究结果，本研究提出如下科学问题：1）膳食单宁酸如何影响肠道微生态？2）膳食单宁酸是否通过影响肠道菌群及其代谢产物调控糖脂代谢？3）膳食单宁酸是否通过肠道菌群代谢产物调控糖脂代谢信号通路？本研究的目的是对上述科学问题进行解答，阐明膳食单宁酸影响肠道菌群调控糖脂代谢的效应及机制，为膳食单宁酸的有效利用提供最新理论基础。

膳食单宁酸作为一种天然多酚类物质，具有许多重要的生物活性。本项目旨在研究膳食单宁酸通过影响肠道菌群调控糖脂代谢的效应及机制研究。采用高脂饮食诱导C57BL/6J雄性小鼠建立肥胖模型，膳食单宁酸干预8周后，比较各组小鼠血糖血脂、肝功能、机体炎症反应、肠道黏膜屏障、肠道菌群测序和粪便中短链脂肪酸含量的变化。研究表明，膳食单宁酸干预处理可使高脂小鼠体重降低，调节糖脂代谢，改善胰岛素抵抗，减轻肝脏氧化应激。此外，膳食单宁酸干预组可以修复高脂饮食引起的肠道屏障损伤，尤其是50 mg/kg/d膳食单宁酸干预组。并且膳食单宁酸对血清内毒素脂多糖(LPS)含量的影响与产生LPS的微生物群的丰度相关。此外，在150 mg/kg/d膳食单宁酸干预组中，膳食单宁酸改变了肥胖相关肠道微生物群的丰度，而在50 mg/kg/d膳食单宁酸干预组中无效。综上所述，不同剂量的膳食单宁酸可能通过不同的途径发挥其抗肥胖作用，这与膳食单宁酸对糖脂代谢、炎症和肠道菌群的影响密切相关。这些发现提示了膳食单宁酸对预防和控制肥胖的潜在作用，为肥胖的防治提供新的思路。