Objective To explore the association between oral microbiota and esophageal carcinogenesis.

Methods A case-control study design was employed. A total of 309 subjects were recruited, consisting of 159 healthy controls, 32 cases of esophageal basal cell hyperplasia, 32 cases of low-grade intraepithelial neoplasia, 14 cases of high-grade intraepithelial neoplasia, and 72 cases of esophageal squamous cell carcinoma. Tongue swab samples were collected for 16S rRNA sequencing. The α-diversity and β-diversity of the microbiota were analyzed, and the characteristics of the microbial communities at different stages of esophageal carcinogenesis were compared. The strength of the association was expressed by odds ratio (OR) and 95% confidence interval (CI).

Results α-diversity analysis indicated significant differences in the observed species number (Sobs) index across various stages of esophageal cancer progression (P<0.001). After adjusting for confounding factors such as age, gender, smoking, and alcohol consumption, the Simpson index was positively correlated with carcinogenesis (P=0.006). β-diversity analysis revealed differences in microbiota structure among the groups. After ordered multinomial logistic regression analysis and adjustment for multiple confounding factors, the relative abundance of Peptostreptococcus (OR: 2.06, 95%CI: 1.22–3.60), Patescibacteria (OR: 1.31, 95%CI: 1.04–1.67), Capnocytophaga (OR: 1.24, 95%CI: 1.05–1.54), and Bacteroidota (OR: 1.02, 95%CI: 1.00–1.05) was positively correlated with carcinogenesis. The relative abundance of Stomatobaculum (OR: 0.57, 95%CI: 0.30–1.00) and Actinobacteriota (OR: 0.95, 95%CI: 0.92–0.98) was negatively correlated with carcinogenesis.

Conclusion Specific oral microbiotas are significantly associated with esophageal carcinogenesis, and synergistic or antagonistic interactions may be observed among the microbiota.