关键词: 大鼠, 2 型糖尿病, 肠道菌群, 16S rRNA 基因测序

Abstract: Objective To compare the composition and diversity of the gut microbiota of type 2 diabetes mellitus ( T2DM) established by SD and GK rats, and to provide some basic data for further application of the two models in the study of T2DM-related Gut microbiota. Method Forty 8-week old SPF male rats were divided into GK group ( n = 20) , SD group ( n = 20) , respectively. The SD groups of rats were injected intraperitoneally with 30 mg / kg of STZ once a day and were fed a high-fat diet, while the diabetic symptoms of GK group rats were induced by high fat diet for 4 weeks, fasting blood glucose ≥ 11. 1 mmol / L was considered as the successful model of T2DM in the two groups. After 6 weeks of modeling, 10 fecal samples were collected from each group of 10 rats, and 16S rRNA gene V3-V4 region was sequenced, the Alpha diversity, Beta diversity, dominant genus and the functional pathways related to gut microbiota in fecal were analyzed. Result There was no difference in alpha diversity and richness between GK and SD T2DM rats, and beta diversity was significantly different in the two groups ( all P< 0. 05) . The dominant genera of T2DM rats in GK group were Lactobacillus, Clostridia _ UCG-014 _ unclassified, Muribaculaceae_ unclassified, Akkermansia and Ruminococcus. And the dominant genera of T2DM rats in SD group were Allobaculum, Lactobacillus, Lachnospiraceae _ NK4A136 _ group, Streptococcus, Ruminococcus, UCG-005 and Ligilactobacillus. The proportion of the same dominant bacterial genus was a significant difference between the two groups. The functional pathways of the gut microbiome of T2DM rats in the two groups were concentrated in the metabolic pathways with amino acid metabolism, glucose metabolism, nucleotide metabolism and lipid metabolism. Conclusion There was no difference in alpha diversity of gut microbiome between GK and SD groups of T2DM rats, but the composition and proportion of gut microbiome were significantly different. The composition proportion of the dominant gut microbiome was changed in the different models.

Key words: rat, type 2 diabetes mellitus, gut microbiome, 16S rRNA gene sequencing