[A preliminary study on salivary microbiota of patients with laryngopharyngeal reflux]

Objective: To investigate the characteristics of salivary microbiota in patients with laryngopharyngeal reflux (LPR). Methods: A case-control study was applied to enroll 60 patients and healthy subjects who were outpatients of the Department of Otorhinolaryngology Head and Neck Surgery of the Eighth Medical Center of the PLA General Hospital from December 2020 to March 2021, including 35 males and 25 females, aged from 21 to 80 (33.75±11.10) years. Thirty patients with suspected laryngopharyngeal reflux were selected as study group and thirty healthy volunteers without pharyngeal symptoms were selected as control group. Their salivary samples were collected, and the salivary microbiota was detected and analyzed by 16S rDNA sequencing. SPSS 18.0 software was used for statistical analysis. Results: There was no significant difference in the diversity of salivary microbiota between the two groups. At the phylum classification level, the relative abundance of Bacteroidetes in the study group was higher than that in the control group[37.86(31.15, 41.54)% vs 30.24(25.51, 34.18)%,Z=-3.46,P<0.01]. And the relative abundance of Proteobacteria in the study group was lower than that in the control group [15.76(11.81, 20.17)% vs 20.63(13.98, 28.82)%, Z=-1.98,P<0.05]. At the genus level, the relative abundance of Prevotella, Lactobacillus, Parascardovia and Sphingobium in the study group was higher than that in the control group(Z values were-2.92, -2.69, -2.05, -2.31, respectively, P<0.05).And the relative abundance of Streptococcus, Cardiobacterium, Klebsiella and Uruburuella of study group was lower than that of control group(Z values were -2.43, -2.32, -2.17, -2.32, respectively, P<0.05). LEfSe difference analysis showed that there were 39 bacteria with significant differences between the two groups, including Bacteroidetes, Prevotellaceae and Prevotella, which were enriched in the study group, and Streptococcaceae, Streptococcus and other taxa, which were enriched in the control group(P<0.05). Conclusion: The changes of the microflora in the saliva between LPR patients and healthy people suggest that the dysbacteriosis might exist in LPR patients, which may play an important role in the pathogenesis and development of LPR.