Oral microbiota dysbiosis in Sjögren's disease occurs independent of hyposalivation.

OBJECTIVES: The objective of this study was to compare the oral microbiota of patients with SjD and controls, and to correlate these findings with clinical variables such as hyposalivation, dental and periodontal status, and the occurrence of oral candidiasis. METHODS: Participants diagnosed with SjD (SjD group) and age- and sex-matched controls without SjD were included. Sociodemographic data, medication use, unstimulated whole salivary flow (UWSF), plaque index (PI), periodontal screening and recording (PSR), decayed, missing, filled teeth index (DMFT) and use of dental prostheses were assessed. Oral Candida spp. carriage was evaluated through colony-forming unit counts and chromogenic agar cultures from oral rinse samples. Oral microbiota was characterized using 16S rRNA gene amplification and sequencing. RESULTS: Clinical data and samples of 61 patients were analysed (SjD group = 27 and control group = 34). Oral health parameters were worse in the SjD group compared with controls. Analysis of microbial diversity in saliva revealed significant differences between the groups. The genera Stenotrophomonas, Streptococcus and Veillonella were more abundant in the SjD group, whereas Haemophilus, Neisseria and Prevotella were more abundant in the control group. The SjD group also exhibited significantly lower overall bacterial diversity, which was associated with greater frequency of moderate and high PI scores and Candida spp. isolates, without association with UWSF. CONCLUSION: These findings of this study suggest that SjD participants presented a dysbiotic and less diverse oral microbiota, and that the observed microbial alterations cannot be explained exclusively by salivary gland-mediated changes in saliva production.