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Non-alcoholic fatty liver disease (NAFLD) has emerged as a leading public health challenge and is closely associated with metabolic syndromes, such as obesity. Intestinal microbiota dysbiosis could play a vital role in the pathogenesis and progression of NAFLD. Tea is the second most popular health drink in the world behind water, and exhibits many health-promoting effects. In this study, the protective effects of different black and dark teas on NAFLD induced by long-term high-fat diet (HFD) exposure and their regulation of gut microbiota were evaluated and explored. The results indicated that supplementation with different black and dark tea extracts could significantly suppress the energy intake, alleviate abnormal accumulation of visceral fat, and prevent obesity, hepatic abnormal lipid deposition and liver steatosis in HFD-fed mice at varying degrees. In addition, Dianhong tea and Liupao tea interventions could significantly decrease the ratio of Firmicutes to Bacteroidetes, and selenium-enriched black tea and selenium-enriched dark rea supplementation could remarkably reduce the relative abundance of Actinobacteria compared to the model group. Moreover, these teas could partly shift the relative abundances of Allobaculum, Roseburia and Dubosiella. Taken together, black teas and dark teas could prevent HFD-induced features of obesity and NAFLD, which might partly be due to the modulation of gut microbiota. [ABSTRACT FROM AUTHOR]

The epidemic of obesity is a serious public health problem. In this study, the effect of theabrownin from dark tea on obesity was evaluated by biochemical tests and nuclear magnetic resonance in C57BL/6J mice fed a high-fat diet. A mixture of antibiotics was used to deplete gut microbiota and then fecal microbiota transplant was used to restore gut microbiota. Untargeted metabolomics was used to reveal the effects of theabrownin on metabolic profiles through gut microbiota. The results showed that theabrownin significantly reduced body weight gain (83.0%) and body fat accumulation (30.29%) without affecting appetite. Also, theabrownin promoted lipid clearance with a hepatoprotective effect. The extra antibiotics disrupted the regulation of theabrownin on weight control while fecal microbiota transplant restored the beneficial regulation. That is, gut microbiota was important for theabrownin to reduce body weight gain. The untargeted metabolomics indicated that 18 metabolites were related to the anti-obesity effect of theabrownin mediated by gut microbiota. Furthermore, phenylalanine metabolism, histidine metabolism, as well as protein digestion and absorption pathway played a role in the anti-obesity of theabrownin. Our findings suggested that theabrownin significantly alleviated obesity via gut microbiota-related metabolic pathways, and theabrownin could be used for the prevention and treatment of obesity. [ABSTRACT FROM AUTHOR]

Aspergillus niger is one of the dominant microorganisms presented in dark tea fermentation. In this study, the biotransformation of steamed green tea leaves fermented by A. niger PW-2 was characterized using metabolomic and proteomic approaches. We observed that, after fermentation, the contents of volatile compounds contributing to the "green" aroma, including linalool, L-α-terpineol and geraniol, decreased significantly. Meanwhile, the astringency taste and contents of metabolites contributing to the taste (catechins) reduced significantly during fermentation. Additionally, the contents of theabrownins, which have health benefits, obviously increased. The bitter and umami tastes were also changed due to the variations in bitter-taste and umami-taste amino acids. We also found that glycoside hydrolases, tannases, catechol oxidases, peroxidases and laccases secreted by A. niger PW-2 were responsible for the metabolism of phenolic compounds and their derivatives (theaflavins, thearubingins and theabrownins). Finally, the metabolic pathways involved in the biosynthesis and degradation of characteristic metabolites were found to reveal the biotransformation characteristics of dark tea fermented with A. niger PW-2. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD) has emerged as a leading public health challenge and is closely associated with metabolic syndromes, such as obesity. Intestinal microbiota dysbiosis could play a vital role in the pathogenesis and progression of NAFLD. Tea is the second most popular health drink in the world behind water, and exhibits many health-promoting effects. In this study, the protective effects of different black and dark teas on NAFLD induced by long-term high-fat diet (HFD) exposure and their regulation of gut microbiota were evaluated and explored. The results indicated that supplementation with different black and dark tea extracts could significantly suppress the energy intake, alleviate abnormal accumulation of visceral fat, and prevent obesity, hepatic abnormal lipid deposition and liver steatosis in HFD-fed mice at varying degrees. In addition, Dianhong tea and Liupao tea interventions could significantly decrease the ratio of Firmicutes to Bacteroidetes, and selenium-enriched black tea and selenium-enriched dark rea supplementation could remarkably reduce the relative abundance of Actinobacteria compared to the model group. Moreover, these teas could partly shift the relative abundances of Allobaculum, Roseburia and Dubosiella. Taken together, black teas and dark teas could prevent HFD-induced features of obesity and NAFLD, which might partly be due to the modulation of gut microbiota.

The epidemic of obesity is a serious public health problem. In this study, the effect of theabrownin from dark tea on obesity was evaluated by biochemical tests and nuclear magnetic resonance in C57BL/6J mice fed a high-fat diet. A mixture of antibiotics was used to deplete gut microbiota and then fecal microbiota transplant was used to restore gut microbiota. Untargeted metabolomics was used to reveal the effects of theabrownin on metabolic profiles through gut microbiota. The results showed that theabrownin significantly reduced body weight gain (83.0%) and body fat accumulation (30.29%) without affecting appetite. Also, theabrownin promoted lipid clearance with a hepatoprotective effect. The extra antibiotics disrupted the regulation of theabrownin on weight control while fecal microbiota transplant restored the beneficial regulation. That is, gut microbiota was important for theabrownin to reduce body weight gain. The untargeted metabolomics indicated that 18 metabolites were related to the anti-obesity effect of theabrownin mediated by gut microbiota. Furthermore, phenylalanine metabolism, histidine metabolism, as well as protein digestion and absorption pathway played a role in the anti-obesity of theabrownin. Our findings suggested that theabrownin significantly alleviated obesity via gut microbiota-related metabolic pathways, and theabrownin could be used for the prevention and treatment of obesity.

Aspergillus niger is one of the dominant microorganisms presented in dark tea fermentation. In this study, the biotransformation of steamed green tea leaves fermented by A. niger PW-2 was characterized using metabolomic and proteomic approaches. We observed that, after fermentation, the contents of volatile compounds contributing to the “green” aroma, including linalool, L-α-terpineol and geraniol, decreased significantly. Meanwhile, the astringency taste and contents of metabolites contributing to the taste (catechins) reduced significantly during fermentation. Additionally, the contents of theabrownins, which have health benefits, obviously increased. The bitter and umami tastes were also changed due to the variations in bitter-taste and umami-taste amino acids. We also found that glycoside hydrolases, tannases, catechol oxidases, peroxidases and laccases secreted by A. niger PW-2 were responsible for the metabolism of phenolic compounds and their derivatives (theaflavins, thearubingins and theabrownins). Finally, the metabolic pathways involved in the biosynthesis and degradation of characteristic metabolites were found to reveal the biotransformation characteristics of dark tea fermented with A. niger PW-2.