Abstract: Objective To explore the difference of intestinal microbiota and metabonomics between male and female rats in the preparation of precancerous esophageal lesion models. 
Methods N-Nitorsos-N-methyl-4-aminobutyric Acid (NMBA) solution (0.30 mg/kg) was subcutaneously injected into female rats and male rats every 3 days. The rats in the control group were not induced, and HE staining was used to observe the pathological histology of esophageal mucosa in each group. Total DNA was extracted from the contents in the cecum of rats, and 16S rRNA gene sequencing and bioinformatics analysis were used to analyze the α and β diversity and then obtain the different bacteria between groups. Non-targeted metabonomics was used to detect metabolites of plasma. 
Results The HE staining results of rat esophageal epithelium showed that after 40 weeks of treatment with NMBA, male rats showed more stable modeling compared with female rats. The 16S rRNA gene sequencing results showed that there was no significant difference in species abundance and evenness of the samples between the two groups, while there were significant differences in the number and distribution of each community. At the genus level, there were significant differences in the expression of intestinal microbiota between the female and male mouse model groups. The metabolomics results showed that there were significant differences in blood metabolism between the male and female mouse model groups, and the metabolites with significant differences were mainly concentrated in oxidized lipids and bile acids. 
Conclusion There are significant differences in intestinal microbiota and metabolomics between female and male mice in the preparation of esophageal precancerous lesion models. 

Key words: esophageal neoplasms, rats, tumorigenesis rate, gut microbiota, metabolomics