【Animal modeling】-Streptozotocin-induced diabetic rat model changes in intestinal flora

  Objective: To observe the changes in the structure and abundance of intestinal flora in streptozotocin-induced diabetic rat model.

  Methods: Twenty-five male SD rats were randomly divided into 10 control group (C) and 15 model group (M). The model group was intraperitoneally injected with 3% STZ at a dose of 30 mg/(kg·bw) for 5 consecutive days. Body weight, blood sugar and other indicators were measured monthly after molding. When the model was established for 4 weeks and 12 weeks, the fresh rectal feces of the rats in each group were collected at the same time. The bacterial 16S rDNA-V3 region in stool samples was sequenced on the Illumina high-throughput sequencing platform, and the structure and abundance of intestinal flora were quantitatively analyzed.

  RESULTS: There was no significant difference in the number of optimized sequences obtained between the model group and the control group (P > 0.05). Compared with the control group, the relative abundance index (Chao1) and diversity index Shannon of the intestinal flora in the model group were decreased (P < 0.05), and the Simpson index was increased compared with the control group (P < 0.05). At the phylum level, the relative abundances of Proteobacteria, Cyanobacteria, Softwall, TM7 and Actinomycetes decreased (P < 0.05). At the genus level, after 4 weeks of modeling, the relative abundance of Lactobacillus in the model group decreased (P < 0.05); the relative abundance of Bacteroides increased (P < 0.05). After 12 weeks of modeling, the relative abundances of Lactobacillus, Bacteroides and Ruminococcus increased in the model group (P < 0.05); the relative abundance of Bifidobacterium decreased (P < 0.05).

  CONCLUSION: The abundance and diversity of gut microbiota in SD rats induced by STZ are reduced, which provides a reference for the study of the relationship between diabetes and gut microbiota.