The Microbiota Is Essential for the Generation of Black Tea Theaflavins-Derived Metabolites

Abstract

BackgroundTheaflavins including theaflavin (TF), theaflavin-3-gallate (TF3G), theaflavin-3′-gallate (TF3′G), and theaflavin-3,3′-digallate (TFDG), are the most important bioactive polyphenols in black tea. Because of their poor systemic bioavailability, it is still unclear how these compounds can exert their biological functions. The objective of this study is to identify the microbial metabolites of theaflavins in mice and in humans.Methods and FindingsIn the present study, we gavaged specific pathogen free (SPF) mice and germ free (GF) mice with 200 mg/kg TFDG and identified TF, TF3G, TF3′G, and gallic acid as the major fecal metabolites of TFDG in SPF mice. These metabolites were absent in TFDG- gavaged GF mice. The microbial bioconversion of TFDG, TF3G, and TF3′G was also investigated in vitro using fecal slurries collected from three healthy human subjects. Our results indicate that TFDG is metabolized to TF, TF3G, TF3′G, gallic acid, and pyrogallol by human microbiota. Moreover, both TF3G and TF3′G are metabolized to TF, gallic acid, and pyrogallol by human microbiota. Importantly, we observed interindividual differences on the metabolism rate of gallic acid to pyrogallol among the three human subjects. In addition, we demonstrated that Lactobacillus plantarum 299v and Bacillus subtilis have the capacity to metabolize TFDG.ConclusionsThe microbiota is important for the metabolism of theaflavins in both mice and humans. The in vivo functional impact of microbiota-generated theaflavins-derived metabolites is worthwhile of further study.

Oat Avenanthramide-C (2c) Is Biotransformed by Mice and the Human Microbiota into Bioactive Metabolites

“…For example, green tea catechins could be biotransformed by gut microbiota to ring-fission metabolites in in vitro models (24). Studies in our group also found that theaflavins, the major polyphenols in black tea, could be metabolized to gallic acid and pyrogallol by gut microbiota (18). In this study, we identified DH-2c, CA, and DH-CA as the metabolites of 2c by the human microbiota.…”

“…Interindividual differences in the composition of gut microbiota has become apparent, which may lead to variations in bioavailability and bioefficacy of dietary compounds, and eventually contribute to personalized nutrition approaches (18,22,25,26). Our present study shows that 2c is almost completely converted to DH-2c, CA, and DH-CA by subject B, but hardly metabolized by subject D within 120-h incubation.…”

“…All the participants avoided oat-rich foods for at least 48 h before fecal collection. Human fecal slurries and fermentation basal medium were prepared as described previously (18). The in vitro fermentation experiment was performed under the following conditions: 10-mL 2c (20 g/L) stock solution, 10-mL fermentation medium, and 1-mL fecal slurry were mixed and then divided into 7 sets of samples (;1.2 mL each) to represent 0-, 12-, 24-, 48-, 72-, 96-, and 120-h time points.…”

Antibacterial activities of the Methanolic extract of Bangladeshi Black tea against various human pathogens

“…25 In this study, we reported that methanolic extract of Bangladeshi black tea showed significant antibacterial activities against a range of pathogenic bacteria. Our results demonstrated that only one hour of incubation with black tea extract caused drastic reduction in bacterial cell number.…”

Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances: Part II – contemporary contextual research

“…6 months) increased microbial diversity and had anti-obesity effects later on in the life of offspring [154]. L. plantarum 299v, L. plantarum DSM 15313 and other probiotics are currently being investigated for their ability to enhance the absorption of active polyphenolic chemicals that would be of relevance to brain health [155,156]. It is not our desire to belabor the point concerning the interaction between food and microbes; however, there are countless other components of traditional diets that could be singled out for relevancy.…”