富含鞣革单宁的食物首先在胃和小肠中水解成鞣花酸,然后通过肠道菌群转化为具有高生物利用度的尿石素。尿石素具有有益的生物学效应,它可以诱导脂肪细胞褐变,改善胆固醇代谢,抑制移植物肿瘤生长,缓解炎症,并通过β3-AR/PKA/p38MAPK下调神经元淀粉样蛋白的形成,ERK/AMPKα/SREBP1,PI3K/AKT/mTOR信号通路,和TLR4,AHR受体。但是据报道,不同个体之间的尿石素生产能力存在差异。因此,探讨尿石素的生物学功能具有重要意义,筛选负责尿石素生物转化的菌株,并探索相应的功能基因。单宁酰基水解酶可以将单宁水解为鞣花酸,Gordonibacter和Ellagibacter属可以将鞣花酸代谢为尿石素。因此,应用“单菌”,“单菌+酶”,和“微生物区系”可以实现尿石素A的生物转化。在这篇综述中,鞣革单宁的来源和代谢途径,以及代谢物的生物学功能机制,尿石素A,正在讨论。阐述了目前获得尿石素A的生物转化策略,为进一步研究尿石素与人类健康的关系提供思路。
Foods rich in ellagic tannins are first hydrolyzed into ellagic acid in the stomach and small intestine, and then converted into urolithins with high bioavailability by the intestinal flora. Urolithin has beneficially biological effects, it can induce adipocyte browning, improve cholesterol metabolism, inhibit graft tumor growth, relieve inflammation, and downregulate neuronal amyloid protein formation via the β3-AR/PKA/p38MAPK, ERK/AMPKα/SREBP1, PI3K/AKT/mTOR signaling pathways, and TLR4, AHR receptors. But differences have been reported in urolithin production capacity among different individuals. Thus, it is of great significance to explore the biological functions of urolithin, screen the strains responsible for biotransformation of urolithin, and explore the corresponding functional genes. Tannin acyl hydrolase can hydrolyze tannins into ellagic acid, and the genera Gordonibacter and Ellagibacter can metabolize ellagic acid into urolithins. Therefore, application of \"single bacterium\", \"single bacterium + enzyme\", and \"microflora\" can achieve biotransformation of urolithin A. In this
review, the source and metabolic pathway of ellagic tannins, and the mechanisms of the biological function of a metabolite, urolithin A, are discussed. The current strategies of biotransformation to obtain urolithin A are expounded to provide ideas for further studies on the relationship between urolithin and human health.