A pilot study of the relationship between salivary microbial characteristics and endocrine and immune function in patients with burning mouth syndrome

Objectives

To explore the potential role of oral bacteria in the pathogenesis of burning mouth syndrome (BMS).

Materials and methods

Fifteen patients with BMS and 15 healthy controls were enrolled in this study. The relative abundance and diversity of salivary bacterial strains were analyzed using metagenomic DNA sequencing. The functionality of non-redundant genes was obtained by comparing the mmseqs2 with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. BMS relating salivary protein markers were detected using enzyme-linked immunosorbent assay (ELISA).

Results

Partial least-squares discriminant analysis (PLS-DA) revealed that the salivary bacterial profiles of the BMS group (mean age: 38.9 ± 2.2 years) differed significantly from those of the control group (mean age: 34.1 ± 2.3 years) in terms of the abundance of dominant phyla, classes, orders, families, genera and species. Functional analysis revealed distinct endocrine and immune functions in the BMS group. The salivary cortisol and α-amylase levels were significantly higher, and salivary interleukn-6 levels were significantly lower in the BMS group than in the control group. Species contribution analysis of endocrine and immune functions revealed that Streptococcus mitis was an important contributor to endocrine and immune functions in the BMS group.

Conclusions

Salivary dysbiosis related to endocrine and immune functions may be a possible cause of BMS.

Clinical relevance

These findings could assist in the diagnosis and therapy of BMS.

Clinical trial number

Not applicable.