Relationship of tongue coating microbiome on volatile sulfur compounds in healthy and halitosis adults.

AIM

This study aims to assess the microbiome variations related to intraoral halitosis and its relationship with volatile sulfur compounds (VSCs) among periodontally healthy Chinese adults.

MATERIAL AND METHODS

Tongue coating samples were collected from 28 periodontally healthy subjects (16 subjects with halitosis and 12 subjects without halitosis) who fulfilled the selection criteria. The organoleptic score (OS) was used to evaluate the halitosis status. The characterization of associated microbial communities was performed using 16S rRNA gene pyrosequencing and metagenomics methods.

RESULTS

A wide range of microbial communities, including 13 phyla, 23 classes, 37 orders, 134 genera, 266 species and 349 operational taxonomic units (OTUs), were detected. The Shannon index values were significantly higher in the halitosis group. Genera, such as Prevotella, Alloprevotella, Leptotrichia, Peptostreptococcus and Stomatobaculum, exhibited significantly higher relative percentages in halitosis samples, when compared to healthy samples. Peptostreptococcus, Alloprevotella, Eubacterium nodatum and Stomatobaculum exhibited significantly positive correlations with the total number of VSCs. Prevotella, Peptostreptococcus, Eubacterium nodatum and Alloprevotella were correlated with increased HS and CHSH concentration values. Bergeyella was correlated with decreased total VSC, HS and CHSH concentration values.

CONCLUSION

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. Tongue coating microbiota can offer important clues in the investigation of the pathogenesis and treatment of halitosis.