The effects of a mixture of antibiotics on the intestinal microbiota and hepatic lipid deposition in hybrid grouper fed bile acids diet

Abstract

As antibiotics-treated animal models provide good insights into the potential causes of the microbiota-dependent changes, we explored the effects of microbiota perturbation driven by a mixture of antibiotics on lipid metabolism and lipid deposition in the liver of hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) fed a bile acid diet in this study. Ninety groupers were randomly fed a bile acids diet (SBD) or a bile acids diet supplemented with antibiotics mixture (ASBD) for a short-term period. The results showed that ASBD treatment significantly decreased the level of hepatic lipid droplets, the content of hepatic triglycerides and total cholesterol, and serum low-density lipoprotein cholesterol, while significantly increasing the content of high-density lipoprotein cholesterol, compared to the SBD group. The fish fed ASBD showed significantly enhanced activities of lipolytic enzymes, expression of lipolytic proteins and transcriptional factors genes, whereas significantly reduced the expression of lipogenic transcriptional factor genes. In addition, the antibiotics treatment significantly increased the abundance of Bacteroidetes, while non-significantly decreasing the Firmicutes/Bacteroidetes ratio (p = 0.061). No significant shifts were observed in the α-diversity indices in SBD and ASBD groups, although the structures and potential functions of the intestinal microbiota were clearly separated. In conclusion, the antibiotics treatment reduced the lipid deposition and altered lipid metabolism via mainly enhancing hepatic lipolysis and slightly reducing hepatic lipogenesis.