Green Tea Polyphenols Modify the Gut Microbiome in db/db Mice as Co-abundance Groups Correlating with the Blood Glucose Lowering Effect.

SCOPE: We investigated and compared the effects of green tea polyphenols - Polyphenon E (PPE) and black tea polyphenols - theaflavins (TFs) on gut microbiota and development of diabetes in db/db mice.

METHODS AND RESULTS: Supplementation of PPE (0.1%) in the diet to female db/db mice for 7 weeks decreased fasting blood glucose levels and mesenteric fat, while increasing the serum level of insulin, possibly through protection against β-cell damage. However, TFs were less or not effective. Microbiome analysis through 16S rRNA gene sequencing showed that PPE and TFs treatments significantly altered the bacterial community structure in the cecum and colon, but not in the ileum. The key bacterial phylotypes responding to the treatments were then clustered into 11 co-abundance groups (CAGs). CAGs 6 and 7, significantly increased by PPE but not by TFs, were negatively associated with blood glucose levels. The OTUs in these CAGs were from two different phyla, Firmicutes and Bacteroidetes. CAG 10, decreased by PPE and TFs, was positively associated with blood glucose levels.

CONCLUSION: Gut microbiota respond to tea polyphenol treatments as CAGs, instead of taxa. Some of the CAGs associated with the blood glucose lowering effect were enriched by PPE, but not TFs. This article is protected by copyright. All rights reserved.