Characteristics Of Salivary Flora Changes In Patients With Benign Prostatic Hyperplasia And Its Correlation

Objective:By examining microorganisms in the saliva of patients with benign prostatic hyperplasia(BPH),we screened for characteristic flora and also studied the correlation between flora imbalance and changes in prostate gland-specific antigen(PSA)levels in patients with BPH.Methods:Between June 2021 and June 2022,50 patients with BPH admitted to the Department of Urology of the First Hospital of Soochow University,the Second People’s Hospital of Wuxi,and the People’s Hospital of Huishan District of Wuxi for lower urinary tract symptoms(LUTS)were used as the BPH group,while 50 healthy people without LUTS symptoms and without imaging suggestive of BPH on physical examination were used as the control group.The clinical data of the two groups were collected,and 2.5 ml of their saliva samples were collected and stored in sterile containers without RNA.saliva samples from the BPH and control groups were purified by targeted amplification of the 16S rRNA V3-V4 region and PCR and then subjected to second-generation sequencing to analyze the characteristics of the salivary microflora.Species diversity and species variability between groups were analyzed using alpha diversity,PCoA,and LEfSe.Pearson correlation analysis was used to compare the correlation between differential flora and PSA levels in the BPH group.Results:The mean age of the BPH group was 68.8±6.44 years and the mean age of the control group was 65.32±11.66 years.There was no statistical difference between the two groups in terms of body mass index,smoking and alcohol consumption(P>0.05).Comparative analysis revealed differences between the BPH group and the control group in terms of salivary microflora.At the phylum level,the proportion of Campilobacterota,Desulfobacterota,Fusobacteriota,Patescibacteria,Spirochaetota and Synergistota bacteria was increased in the BPH group compared to the control group(all FDR<0.05),but Actinobacteriota and Cyanobacteria were reduced(FDR<0.05).At the genus level,comparison of bacterial genera with more than 1%total abundance between the two groups revealed that 12 bacterial genera had increased proportions in the BPH group compared to the control group,including Campylobacter,Candidatus-Saccharimonas,Capnocytophaga.Clostridia-UCG-014.Filifactor,Leptotrichia,Megasphaera,Oribacterium,Selenomonas,Treponema,Veillonella and fSaccharimonadaceae,g-TM7(Saccharimonadaceae a genus of the family Saccharimonadaceae)(FDR all<0.05).Within the BPH group four bacterial genera were decreasing,such as Actinomyces,Lachnoanaerobaculum,Rothia,oLactobacillales,f-P5D1-392(a genus in the order Lactobacillales).Significant differences in the bacterial profiles of the two groups at different levels were identified by linear discriminant analysis.At the phylum level,Spirochaetota,Fusobacteriota and Patescibacteria were considered as biomarkers for the identification of BPH(LDA≥2,P<0.05),and at the genus level,Capnocytophaga,Leptotrichia,Selenomonas Treponema,and Veillonella were considered as biomarkers of BPH(LDA≥2,P<0.05).The presence of flora was found to affect the level of prostate-specific antigens in the BPH group of patients by Pearson correlation analysis,e.g.,an increase in Campylobacter in BPH patients was positively correlated with serum fPSA(r=0.399,P=0.009).However,the increase in Oribacterium levels in BPH patients was negatively correlated with the fPSA/tPSA ratio(r=-0.337,P=0.029).Conclusion:There is a dysbiosis of salivary microflora in patients with BPH,manifested by an increase in harmful flora such as Clostridia-UCG-014,Oribacterium,Filifactor,and a decrease in beneficial bacteria such as o-Lactobacillales,f-P5D 1-392.dysbiosis in patients with BPH affects the level of PSA expression,which suggests that possible existence of a saliva-prostate axis,which needs to be further investigated.Some specific biomarkers exist in the salivary microbiota.The detection of differential flora contributes to our in-depth understanding of the pathogenesis and clinical symptoms of BPH,and saliva samples are easy to perform clinically as non-invasive tests.