Reshaped fecal gut microbiota composition by the intake of high molecular weight persimmon tannin in normal and high-cholesterol diet-fed rats
It has been proposed that the gut microbiome may be related to obesity, and diet-induced obesity may induce changes in the gut microbiota composition. Our previous studies suggested that persimmon tannin (PT), which is highly polymerized and non-absorbable in the intestine, showed anti-hyperlipidemic and cholesterol-lowering effects in animal models. Considering that the possible composition modification effects of PT on intestinal bacteria might contribute to its anti-hyperlipidemic and cholesterol-lowering effects in vivo, in this study, we determined whether the PT administration could modify the gut microbiota in both normal diet-fed and high-cholesterol (HC) diet-fed rats, and how PT altered the bacterial composition in both normal and HC fed rats. Sprague-Dawley rats were randomly divided into eight groups, and fed with either a normal or an HC diet supplemented with or without a low/medium/high dose of PT (50 (LPT), 100 (MPT), 200 (HPT) mg per kg body weight (BW) per day, respectively) for 4 weeks. On days 0, 7, 14, 21 and 28, feces were collected and prepared for the microbiota and physicochemical analysis. The results showed that LPT and MPT supplementation significantly altered the gut microbiota composition by increasing the Bacteroidetes/Proteobacteria ratio in both normal diet-fed and HC diet-fed rats. LPT also decreased the Firmicutes/Bacteroidetes ratio in normal diet-fed rats and MPT decreased the Firmicutes/Bacteroidetes ratio in HC diet-fed rats. Both LPT and MPT supplementation induced a significant alteration in specific bacterial species after 14 days of treatment. The relative abundance of Bifidobacterium sp. and Lactobacillus sp. was increased by both LPT and MPT treatment, and that of Escherichia coli and Enterococcus was reduced. Our data also indicate that there is a correlation between the changes in bacterial composition and the changes in short-chain fatty acid (SCFA) metabolism. However, HPT supplementation altered the gut microbiota at the phylum and species levels in an adverse way.