The effect of Lactobacillus rhamnosus hsryfm 1301 on the intestinal microbiota of a hyperlipidemic rat model

BACKGROUND Growing evidence indicates that intestinal microbiota regulate our metabolism. Probiotics confer health benefits that may depend on their ability to affect the gut microbiota. The objective of this study was to examine the effect of supplementation with the probiotic strain, Lactobacillus rhamnosus hsryfm 1301, on the gut microbiota in a hyperlipidemic rat model, and to explore the associations between the gut microbiota and the serum lipids. METHODS The hyperlipidemic rat model was established by feeding rats a high-fat diet for 28 d. The rats' gut microbiota were analyzed using high-throughput sequencing before and after L. rhamnosus hsryfm 1301 supplementation or its fermented milk for 28 d. The serum lipids level was also tested. RESULTS The rats' primary gut microbiota were composed of Bacteroidetes, Firmicutes, Proteobacteria, Spirochaetes and Verrucomicrobia. The abundance and diversity of the gut microbiota generally decreased after feeding with a high-fat diet, with a significant decrease in the relative abundance of Bacteroidetes, but with an increase in that of Firmicutes (P < 0.05). Administration of L. rhamnosus hsryfm 1301 or its fermented milk for 28 d, could recover the Bacteroidetes and Verrucomicrobia abundance and could decrease the Firmicutes abundance, which was associated with a significant reduction in the serum lipids' level in the hyperlipidemic rats with high-fat diet induced. The abundance of 22 genera of gut bacteria was changed significantly after probiotic intervention for 28 d (P < 0.05). A positive correlation was observed between Ruminococcus spp. and serum triglycerides, Dorea spp. and serum cholesterol (TC) and low-density lipoprotein (LDL-C), and Enterococcus spp. and high-density lipoprotein. The Butyrivibrio spp. negatively correlated with TC and LDL-C. CONCLUSIONS Our results suggest that the lipid metabolism of hyperlipidemic rats was improved by regulating the gut microbiota with supplementation of L.rhamnosus hsryfm 1301 or its fermented milk for 28 d.