Effect of High-fat Diet on the Structure of Gut Microbiota in Human Flora-associated Mice

Abstract

In order to explore the relationship among diet, obesity and intestinal microbiota, high-fat diet was used to establish obese human flora-associated(HFA) mouse model to investigate the effect of high fat diet on the structure of gut microbiota in HFA mice. Totally 20 pathogen-free mice were inoculated with fecal suspension derived from a healthy volunteer to obtain HFA mice. The HFA mice were fed a control or a high-fat diet for 8 weeks. Body weight, blood glucose and blood fat were determined and the change in gut microbiota was analyzed by PCR-DGGE. Results showed that body weight, liver weight, fat tissue weight and serum total triglyceride level revealed a significant increase( P 0.01) in the high-fat group when compared with the control group. Blood glucose level also increased significantly( P 0.05) in high-fat diet-fed HFA mice. The gut bacterial diversity index of the high-fat group significantly increased( P 0.05). The abundance of the dominant bacteria at zero time reduced, but the abundance of bacteria that were not dominant at zero time increased. DNA sequencing showed that high-fat diet may induce Staphylococcus lentus, Staphylococcus vitulinus and Shigella flexneri to bloom in the gut of HFA mice. An obese HFA mouse model was successfully established by feeding a high-fat diet and high-fat diet obviously altered the structure of gut microbiota in HFA mice. The composition and bacterial abundance of intestinal flora in high-fat diet-feed HFA mice greatly changed, leading to intestinal dysbacteriosis. It suggests that human-derived intestinal flora may be involved in the development of obesity caused by imbalanced dietary profile.