Objective To analyze the differences in intestinal microbiota and transcriptomics between N-methyl-N'-nitro-n-nitrosoguanidine (MNNG) gastric cancer rats and normal rats, in order to explore the intestinal microbiota and transcriptomic characteristics of MNNG gastric cancer rats, and to analyze the correlation between the two, so as to provide a reference for related studies using MNNG gastric cancer rats as a model. Methods A total of 12 Wistar rats were randomly divided into normal (NM) and gastric cancer (GC) groups, the gastric cancer group was given a concentration of 20 mg/mL of MNNG by gavage, the dose was 100 g/mL, once a day, and the normal group was given the same dose of normal saline gavage, and the samples were collected for testing after 16 weeks of continuous intervention. The gastric tissues of rats were collected and stained by HE staining to observe the morphological changes of the gastric mucosa of the two groups, and the expression levels of differential genes were detected by transcriptome sequencing. Sterile EP tubes collect cecal contents for 16S rRNA sequencing. Results 1.Macroscopic observation and HE results: The volume of gastric tissue mucosa in the NM group was normal, the surface was shiny, the gastric wall was elastic, the mucosal folds were regular, there was no hyperplasia and no bleeding points, and the gastric mucosa volume of the gastric tissue in the GC group was reduced, the gastric wall was thinned, the elasticity was poor, the folds were disordered and irregular, and there was a bulge accompanied by yellow-black keratinosis. HE staining, the squamous epithelial layer, submucosal layer and muscular layer of the gastric mucosa in the NM group were clear and there was no proliferation and keratosis, while the gastric mucosal layer and cell polarity disorder in the GC group were different, the cell morphology was different, the squamous epithelial layer was destroyed, the squamous epithelial cells proliferated and keratinized, and proliferated downward to invade the muscle, and the modeling was successful. 2. The results of intestinal microbiota sequencing showed that the abundance of Akkermansia and Lactobacillus in MNG gastric cancer rats decreased significantly, and the abundance of Rumen coccaceae, Prevonella and Blauter increased significantly. 3. The three key pathways obtained by transcriptomic sequencing KEGG pathway enrichment analysis were amebiasis, systemic lupus erythematosus and PI3K-AKT signaling pathway, and the five differential genes enriched to these three pathways were MCPT8I2, IGH-6, IGHG1, ACTN2 and VEGFD. 4. The results of combined analysis of intestinal microbiota and transcriptomics showed that _UCG-005, Prevonella _UCG-003 and Brautella may be positively correlated with amebiasis, systemic lupus erythematosus and PI3K-AKT signaling pathway. Conclusions The abundance of intestinal microbiota in gastric cancer rats formed by MNNG gavage is different from that of normal rats, and the up-regulated MCPT8I2, IGH-6, IGHG1, ACTN2 and VEGFD may be the differential genes of gastric cancer induced by MNNG gavage, and the combined analysis of intestinal microbiota and differential genes suggests that the mechanism of MNNG carcinogenesis may be mainly related to the destruction of gastric mucosa and the inflammatory response.