Abstract
BACKGROUND: Burning mouth syndrome (BMS) is a chronic neuropathic orofacial pain condition that remains challenging to manage due to its unclear etiology and limited treatment options. While multiple systemic factors have been proposed, emerging evidence suggests that oral microbial dysbiosis may contribute to neuroinflammatory and pain-related mechanisms. However, the role of the oral microbiota in BMS remains insufficiently understood. SUMMARY: This review examines current evidence regarding the potential association between oral microbiota and BMS, with emphasis on hormonal regulation, immune function, and micronutrient balance. A comprehensive literature search identified studies reporting systemic alterations in patients with BMS. Available evidence suggests that BMS may be associated with changes in sex hormones, thyroid hormones, and neuroendocrine stress responses, potentially influenced by oral microbial composition. Alterations in immune mediators, particularly interleukin-6, and micronutrient imbalances such as vitamin B12 deficiency have also been reported in a subset of patients. These interconnected pathways may contribute to peripheral and central neuropathic pain mechanisms underlying BMS symptoms. KEY MESSAGES: (i) Oral microbiota may interact with hormonal, immune, and micronutrient pathways relevant to BMS. (ii) The relationship between oral dysbiosis and BMS appears complex and potentially bidirectional. (iii) Further clinical and mechanistic studies are needed to clarify these interactions and inform targeted therapies.