Fermentation in vitro of EGCG, GCG and EGCG3"Me isolated from Oolong tea by human intestinal microbiota

In the present study, EGCG, GCG and EGCG3"Me were prepared from Chinese Oolong tea by extraction with hot water and simple purification procedures of polyamide column chromatography and Toyopearl HW-40S column chromatography. Then, the effects of EGCG, GCG and EGCG3"Me on human intestinal microbiota in vitro were evaluated by monitoring the bacterial populations and analyzing the concentrations of short-chain fatty acids (SCFA) at different fermentation times. As a result, EGCG, GCG and EGCG3"Me promoted the growth of Bifidobacterium spp. and Lactobacillus / Enterococcus groups and exhibited inhibitory effects on the growth of Bacteroides – Prevotella , Clostridium histolyticum and Eubacterium – Clostridium groups, while they did not affect the population of total bacteria. Moreover, the total SCFA concentrations in cultures with EGCG, GCG and EGCG3"Me were relatively higher than that of the control. Together, these results suggest that EGCG, GCG and EGCG3"Me have potential prebiotic-like activity by modulating intestinal microbiota and generating SCFA, contributing to the improvements of host health.