Abstract: Objective: To study the salivary bacterial diversity of college students with different dietary habits through high throughput sequencing analysis of 16S rRNA gene. Methods: A total of 36 subjects were selected for a questionnaire survey including 19 students with a preference for meat having a meat-dominated diet (group A), and 17 students with a preference for vegetables having a vegetable-dominated diet (group B). Saliva samples were collected to extract DNA, followed by polymerase chain reaction (PCR) amplification and high-throughput sequencing of bacterial 16S rRNA V3–V4 region using the Illumina platform. The bacterial community structure and diversity were analyzed using the QIIME software. Results: A total of 990 286 high-quality reads were obtained and clustered into 212 operational taxonomic units (OTUs) for further analysis. A total of 16 bacterial phyla and 143 genera were detected. The diversity analysis of salivary microbiota showed that at the phylum level, SR1, Fusobacteria, Candidatus and Saccharibacteria were significantly decreased in group A as compared to group B; at the genus level, the relative abundance of the dominant genera Peptostreptococcus, Parvimonas, Eubacterium, Saccharibacteria_genera_incertae_sedis, SR1_genera_incertae_sedis, Catonella, Mogibacterium, and Solobacterium in group A were significantly lower than in group B, while the opposite was observed for the genus Corynebacterium (P＜0.05). Conclusion: Human saliva has a complex microbial community structure. Dietary habits in college students (meat eaters and vegetarians) may have a significant influence on the structure of the oral microbial community.

Key words: dietary habits, microbiome, bacterial diversity, high throughput sequencing of 16S rRNA gene, QIIME