Abstract:Gut microbiotas are closely related with the obesity of their host. Pseudo germ-free mice are a useful animal model for studying the relationship of gut microbiota with obesity and other related diseases. Twenty C57BL/6J eight-week-old male mice were administered with antibiotic cocktails in drinking water to remove the gut microbiota to establish the pseudo germ-free mouse model. These mice were randomly divided into two groups: control (CONV) group and high fat (HF) group, which were fed with a normal diet and a high-fat diet for eight weeks, respectively. Meanwhile, 20 specific-pathogen-free (SPF) mice were used as controls. Body weight, serum glucose levels, serum lipid levels, and insulin concentrations of the mice were measured by normal methods, and the areas of fat cells were calculated using software. The results revealed that body weight, fat pad, and perirenal fat weight of the HF pseudo germ-free mouse group were significantly lower than those of the HF SPF mouse group (p<0.001), and the insulin level and areas of fat cells in the HF pseudo germ-free mouse group were also significantly lower than those of SPF mice（p<0.01）. Pseudo germ-free mice in the HF diet group showed low bodyweight and a low-fat phenotype, which were extremely similar to those of germ-free mice. As a result, the pseudo germ-free mouse model, established using antibiotic cocktails, can be used to predict modulation results in germ-free mice and is an ideal animal model for exploring the relationship between gut microbiota and diseases.
