Green tea polyphenol (epigallocatechin-3-gallate) improves gut dysbiosis and serum bile acids dysregulation in high-fat diet-fed mice

Abstract

Gut microbiota have profound effects on bile acid metabolism by promoting deconjugation, dehydrogenation, and dehydroxylation of primary bile acids in the distal small intestine and colon. High fat diet induced dysbiosis of gut microbiota and bile acid dysregula tion may be involved in the pathology of steatosis in patients with non alcoholic fatty liver disease. Epigallocatechin 3 gallate (EGCG), the most abundant polyphenolic catechin in green tea, has been widely investigated for its inhibitory or preventive effects against fatty liver. The aim of the present study was to investigate the effects of EGCG on the abundance of gut microbiota and the composition of serum bile acids in high fat diet fed mice and determine the specific bacterial genera that can improve the serum bile acid dysregulation associated with EGCG anti hepatic steatosis action. Male C57BL/6N mice were fed with the control diet, high fat diet, or high fat diet + EGCG at a concentration of 0.32% for 8 weeks. EGCG significantly inhibited the increases in weight, the area of fatty lesions, and the triglyceride content in the liver induced by the high fat diet. Principal coordinate analysis revealed significant differences in microbial structure among the groups. At the genus level, EGCG induced changes in the micro biota composition in high fat diet fed mice, showing a significantly higher abundance of Adlercreutzia, Akkermansia, Allobaculum and a significantly lower abundance of Desulfovibrionaceae. EGCG significantly reversed the decreased population of serum primary cholic acid and β muricholic acid as well as the increased popula tion of taurine conjugated cholic acid, β muricholic acid and deoxy cholic acid in high fat diet fed mice. Finally, the correlation analysis between bile acid profiles and gut microbiota demonstrated the contribution of Akkermansia and Desulfovibrionaceae in the improvement of bile acid dysregulation in high fat diet fed mice by treatment with EGCG. In conclusion, the present study suggests that EGCG could alter bile acid metabolism, especially taurine deconjugation, and suppress fatty liver disease by improving the intestinal luminal environment.

Mechanisms of Interactions between Bile Acids and Plant Compounds—A Review

“…The referenced studies indicate that plant polyphenols may interact with bile acids on a molecular level, which may be due to hydrophobic interactions. Besides these direct polyphenol-induced alterations of the bile acid pool, polyphenols are described to significantly change microbiota compositions and affect gen expressions linked to bile acid metabolism [108][109][110]. For instance, resveratrol was reported to decrease ileal bile acid contents, repress FXR, and increase CYP7A1 and bile acid synthesis.…”

Oral, but not rectal delivery of epigallocatechin-3-gallate alleviates colitis by regulating the gut microbiota, oxidative stress, inflammation, and barrier integrity

“…Consistently, Akkermansia has shown similar correlation with that from oral therapy of EGCG in response to prophylactic EGCG. Consistent with it, numerous studies have already paid attention to the interplay between gut microbiome regulated by green tea polyphenols and alleviation or preventing in diseases and obesity, and the key microbe Akkermansia plays crucial role [47][48][49]. As a common intestinal commensal bacterium, Akkermansia has an anti-in ammatory role [50,51].…”

Role of gut microbiota via the gut-liver-brain axis in digestive diseases

“…Feng et al[ 125 ] found that the traditional Chinese medicine Qushi Huayu Decoction (QHD) promotes the formation of regulatory T cell-induced microbiota in the gut, and at the same time enhances the liver′s antioxidant mechanism and decreases liver lipid synthesis; and (5) Polyphenols. Recently, animal studies showed that Raw Bowl Tea polyphenol not only reduced the level of Firmicutes in the feces of mice with NAFLD, and increased the minimum levels of Bacteroides and Akkermansia, but also reduced the production of inflammatory factors and alleviated the pathological injuries of liver and small intestinal tissues[ 126 ], moreover, green tea polyphenol (epigallocatechin-3-gallate) can affect the composition of the gut microbiota of mice fed a HFD and change the metabolism of bile acids[ 127 ]. These studies suggest that polyphenol has great therapeutic potential for patients with NAFLD.…”