Abstract:The study explored the effects of colonization by different Bacteroides strains on serum biochemical indices and short-chain fatty acids in pseudo germ-free mice.Mice were gavaged with an antibiotic mixture to eliminate the majority of intestinal microbes in order to establish a pseudo germ-free mice model.Mice were then randomly divided into the model group and four Bacteroides colonization groups.The transplantation in the four groups with human-derived viable bacteria with strong acid resistance was carried out by gavage.The effects of the Bacteroides strains on mice were evaluated by measuring organ and serum biochemical indices and determining short-chain fatty acid content.Bacteroides thetaiotaomicron JCM 5827 and Bacteroides vulgatus ATCC 8482 colonized better than the other two strains following their delivery via gavage.Compared with the model group，the Bacteroides colonization groups had significantly higher levels of serum total protein，serum albumin，and cecal butyric acid.The results indicated that colonization of the intestine by Bacteroides strains may have a positive effect on nutrient absorption and maintenance of intestinal health in mice with dysbacteriosis.