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

摘要： 目的 比较 SD 和 GK 两个品系大鼠建立的 2 型糖尿病( T2DM) 模型肠道菌群组成和多样性的异同,为探索 两模型在 T2DM 相关肠道菌群研究中的进一步应用提供背景数据。 方法 采用 8 周龄 SPF 级雄性 SD 和 GK 大鼠 各 20 只,SD 组大鼠高脂饲料饲喂 6 周后,单次腹腔注射 30 mg / kg 的链脲佐菌素( STZ) ,GK 组大鼠高脂饲料诱导 4 周后出现糖尿病症状,两组大鼠空腹血糖≥11. 1 mmol / L 为 T2DM 建模成功,分别收集每组 10 只大鼠建模成功 6 周后的洁净粪便各 10 份,进行 16S rRNA 基因 V3-V4 区测序,分析粪便中肠道菌群的 Alpha 多样性、Beta 多样性、优 势菌属及肠道菌群相关的功能通路。 结果 SD 组与 GK 组大鼠肠道菌群的 Alpha 多样性和丰富度没有显著差异, 两组大鼠肠道菌群 Beta 多样性指数显著不同 (均 P<0. 05) 。 GK 组 T2DM 大鼠肠道的优势菌属为乳酸杆菌属、未 分类梭菌属_UCG_014、未分类鼠杆菌科、阿克曼菌和瘤胃球菌属;SD 组 T2DM 大鼠的优势菌属为异杆菌属、乳酸杆 菌属、毛螺菌科_NK4A136 组、链球菌属、瘤胃球菌属、UCG-005 和联合乳酸杆菌属;两组的优势菌属在组成和比例 上差异很大。 两组 T2DM 大鼠肠道菌群的功能通路主要集中在氨基酸代谢、糖代谢、核苷酸代谢和脂代谢为主的 代谢途径中。 结论 两组 T2DM 大鼠肠道菌群 Alpha 多样性无差异,但肠道菌群的组成及比例差异较大,优势菌群 在不同 T2DM 模型中的组成比例发生了改变。

关键词: 大鼠, 2 型糖尿病, 肠道菌群, 16S rRNA 基因测序