Association between oral microbiome dysbiosis and Sjogren Syndrome. A systematic review of clinical studies.

OBJECTIVES: This systematic review investigates the association of oral microbiome dysbiosis with Sjogren Syndrome (SS). MATERIALS AND METHODS: Indexed databases (PubMed/Medline, EMBASE, OVID, Web of Science, and Scopus) were independently searched for relevant manuscripts published until August 2024. Clinical studies on oral microbial flora count and diversity in SS patients were included. Risk of bias across individual studies was performed using the Risk of Bias in Nonrandomized Studies of Interventions tool. RESULTS: Out of the initial 295 studies, 15 clinical studies met the selection criteria. The protocols were similar across the studies but varied in diagnostic criteria for SS, salivary flow estimation methods, dental and periodontal status findings, and the type of oral microbes observed. Out of 15 studies, 14 showed an alteration in the oral microbiome and differences in microbial diversity in SS patients. Higher oral microbial counts of Prevotella, Viellonella, and Firmicutes in SS were reported, whereas a higher prevalence of caries-associated bacteria Streptococcus, Lactobacillus, and Viellonella was found in SS patients. Overall, the studies had a low risk of bias. CONCLUSIONS: The findings of the present review have shown the existence of significant oral microbial dysbiosis and differences in microbial diversity in SS patients compared to healthy subjects. Future well-designed longitudinal studies are needed to validate the results.