Abstract：
Multiple beneficial effects have been attributed to green tea catechins (GTCs). However, the bioavailability of GTCs is generally low, with only a small portion directly absorbed in the small intestine. The majority of ingested GTCs reaches the large intestinal lumen, and are extensively degraded via biotransformation by gut microbiota, forming many low-molecular-weight metabolites such as phenyl-γ-valerolactones, phenolic acids, butyrate, and acetate. This process not only improves the overall bioavailability of GTC-derived metabolites but also enriches the biological activities of GTCs. Therefore, the intra- and inter-individual differences in human gut microbiota as well as the resulting biological contribution of microbial metabolites are crucial for the ultimate health benefits. In this review, the microbial degradation of major GTCs was characterized and an overview of the in vitro models used for GTC metabolism was summarized. The intra- and inter-individual differences of human gut microbiota composition and the resulting divergence in the metabolic patterns of GTCs were highlighted. Moreover, the potential beneficial effects of GTCs and their gut microbial metabolites were also discussed. Overall, the microbial metabolites of GTCs with higher bioavailability and bioactive potency are key factors for the observed beneficial effects of GTCs and green tea consumption.
摘要：
绿茶儿茶素（GTC）具有多种有益作用。然而,GTC的生物利用度普遍较低，只有一小部分直接被小肠吸收。大多数摄入的GTC到达大肠腔，并通过肠道微生物群的生物转化广泛降解，形成许多低分子量代谢物，如苯基-γ-戊内酯，酚酸，丁酸盐,和醋酸盐。该过程不仅提高了GTC衍生代谢物的整体生物利用度，而且丰富了GTC的生物活性。因此,人类肠道微生物群的个体内部和个体间差异以及由此产生的微生物代谢物的生物学贡献对于最终的健康益处至关重要。在这次审查中,对主要GTC的微生物降解进行了表征，并概述了用于GTC代谢的体外模型。强调了人类肠道微生物群组成的个体内部和个体之间的差异以及GTC代谢模式的差异。此外，还讨论了GTC及其肠道微生物代谢产物的潜在有益作用。总的来说,具有较高生物利用度和生物活性效价的GTC的微生物代谢产物是观察到的GTC和绿茶消费有益效果的关键因素。
