Abstract: Objective　 To investigate whether there are intraductal or oral dysbacteriosis in patients with sialolithiasis, and to explore the relationship between bacteria and the occurrence of sialolithiasis. Method A total of 20 patients with sialolithiasis (1 parotid and 19 submandibular gland) were enrolled in the study as the experimental group. Samples of stone, salivary in oral cavity or intraduct were collected. A total of 20 healthy volunteers were included in the study as the control group. Samples of salivary in oral cavity or intraduct were collected. The bacterial DNA of the extracted samples was amplified by enzyme chain polymerization. The Roche high-throughput 454 pyrosequencing technology was used to sequence the PCR amplicons of the 16S rRNA V1-V3 variable region of bacteria. The sequencing data were further analyzed by using bioinformatics methods to identify the bacterial components and communities. The differences between the experimental and control groups were compared. Result DNA sequencing of saliva and stone samples was successfully performed. Sample sparse curves showed that the sequencing depth was sufficient, and the coverage coverage depth (Coverage index) met the experimental requirements. There was no difference in the biological diversity of intraductal saliva and intraoral microbiota between the experimental group and the control group. There was also no difference in the biological diversity between the stone sample and the intraductal saliva (P>0.05). The Shanno index, Chao index, and ACE index were higher in intraductal saliva than oral cavity (P<0.05). Intraductal microbiota structure comparison showed that Fusobacterium in the experimental group was significantly higher than the control group (p <0.05). At genus level, Prevotella, Porphyromonas and Neisseria were significantly reduced in the experimental group (P<0.05). The comparison of bacterial structures in the oral cavity showed that at the phylum level, Proteobacteria was significantly higher in the experimental group than in the control group (P<0.05). At genus level, Proteus, Streptococcus, and Veillonococcus in the experimental group were significantly lower than the control group (P<0.05). Conclusions The structure and diversity of microbiota in the stone sample are similar to salivary gland duct. The microbial diversity in the salivary gland duct is significantly higher than oral cavity. There is a significant difference in the microbial community between sialolithiasis patients and controlled subjects. There is a dysbacteriosis in the oral and salivary gland ducts of sialolithiasis patients.

Key words: sialolithiasis, microbiota, 16s rRNA, pyrosequencing