Project description:Pu-erh tea has attracted increasing attention worldwide because of its special flavor and health effects, but its impact on composition and function of the gut microbiota remains unclear. The aim of this study was to investigate effects of aqueous extracts of fermented (ripe) and non-fermented (raw) Pu-erh teas on the composition and function of intestinal microbiota of rats with diet-induced obesity. We conducted a comparative metagenomic and metaproteomic investigation of the microbial communities in cecal samples taken from obese rats administrated with or without extracts of raw and ripe Pu-erh tea. By analyzing the composition and diversity of 16S rRNA amplicons and expression profiles of 814 distinct proteins, we found that, despite differences in the chemical compositions of the raw and ripe Pu-erh tea, administration of either at two different doses (0.15 and 0.40 g/Kg body weight), significantly (P<0.05) increased community diversity, and changed the composition of the cecal microbiota by increasing the relative abundances of Firmicutes and decreasing those of Bacteroidetes. Community metabolic processes including sucrose metabolism, glycolysis, syntheses of proteins, rRNA and antibiotics were significantly (P<0.05), or had a tendency (0.10<P<0.05) to be, promoted by enriching relevant enzymes. Furthermore, evidences from population, molecular and metabolic levels have shown that polyphenols of raw Pu-erh tea and their metabolites can promote potentially the growth of Akkermansia municiphila by stimulating the type II and III secretion system protein, elongation factor Tu, and glyceraldehyde-3-phosphate dehydrogenase. This study has provided new evidences for the prebiotic effects of Pu-erh tea.
