Research Of Microbiome Characteristics And Breath Detection In Halitosis

Objective:To establish a more objective and targeted method for detecting malodor with gas chromatography mass spectrometry to analyze the composition of sulfides,and to assess the microbiome variations related to intraoral halitosis and its relationship with VSC among periodontally healthy Chinese adults.Methods:(1)The gas samples from 65 subjects were tested.The exhaled breath odor of halitosis patients and healthy controls was detected by the gas chromatography mass spectrometry to analyze the composition of sulfides.Compared with the organoleptic method and portable sulfide detectors and portable gas chromatographs.(2)Tongue coating and saliva samples were collected from 28 periodontally healthy subjects(16 with halitosis and 12 without halitosis)fulfilling the selection criteria.The characterization of associated microbial communities was performed using 16S rRNA gene pyrosequencing and metagenomics methods.(3)Correlation analysis was performed between microbial communities and VSC detected by the portable sulfide detectors and portable gas chromatographsResults:(1)Compared with the organoleptic method and portable sulfide detectors and portable gas chromatographs.The total sulfide values measured by the three instruments are significantly positively correlated with each other.(2)A wide range of microbial communities including thirteen phyla,23 classes,37orders,134 genera,266 species and 349 operational taxonomic units(OTUs)were detected.The halitosis group had a higher microbial diversity than the control group.The composition,structure,and abundance of microorganisms in different sampling sites with halitosis are significantly various.Genera such as Prevotella,Alloprevotella,Leptotrichia,Peptostreptococcus,and Stomatobaculum showed significantly higher relative percentages in the halitosis than in the healthy samples.(3)Peptostreptococcus,Alloprevotella,Eubacterium nodatum and Stomatobaculum showed significantly positive correlations with the total number of VSC.Prevotella,Peptostreptococcus,Eubacterium nodatum,and Alloprevotella were correlated with increased H₂S and CH₃SH concentration values.Bergeyella was correlated with decreased VSC,H₂S and CH₃SH concentration values.Conclusions:Gas chromatography mass spectrometry can be used in the clinical diagnosis of halitosis.The choice of sampling site has a great impact on the research results.Microbial diversity was higher in the halitosis group than in the control group,and several bacteria were significantly correlated to halitosis.Furthermore,there were correlations between tongue bacterial composition structure and VSC gases.The present study provides new evidence of microbial communities related to intraoral halitosis and detection methods,offering new theoretical basis for the diagnosing,pathogenesis,and treatment of halitosis.