Influences of high-fat diet and methanogens inhibitor on the cecal microbiota and fat metabolism in C57BL/6J mice

Abstract:

Abstract:［Objective］The aim of the study was to investigate the influences of high-fat diet and methanogens inhibitor (bromochloromethane，BCM) on the gut microbiota and fat metabolism in mice.［Methods］Thirty two female C57BL/6J mice were randomly divided into 4 groups: fed respectively by Low-fat diet，Low-fat diet + BCM，High-fat diet and Highfat diet + BCM． BCM was administrated through drinking water for six weeks． The body weight of mice was recorded every week．At the end of experiment，the blood was collected for serum biochemical analysis． Bacterial communities in cecal digesta were analyzed by denaturing gradient gel electrophoresis (DGGE) and real-time PCR． VFA (volatile fatty acid) concentrations in feces were determined by gas chromatography． Expressions of fat-related genes in liver were analyzed using real-time PCR．［Results］DGGE analysis shows that samples from mice fed with high-fat diet gathered together，and separated with samples from low-fat diet group． However，both the fat level in diet and BCM treatment had no effect on the numbers of total bacteria，sulfate reducing bacteria and methanogens．The acetate proportion in feces was significantly decreased (P＜0.05) when fed high-fat diet to mice (P＜0.05)．BCM treatment significantly increased the propionate proportion (P＜0.05)．High-fat diet also significantly increased the levels of high-density lipoprotein cholesterol (HDL-C)，low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TG) in blood (P＜0.05)．High-fat diet up-regulated the expression of TGH gene (P＜0.05)．［Conclusion］High-fat diet affected cecal microbiota and fat metabolism of mice，whereas BCM treatment had little effect．