Oral Cellular Homeostasis and Occupational Wellbeing in Healthcare Professionals Under the Lens of Salivary, Immune, and Microbiome Mechanisms

Background: Healthcare professionals experience continuous biological and psychosocial stressors that may disturb oral and systemic homeostasis. Alterations in salivary secre-tion, mucosal immunity, and microbiome composition reflect adaptive cellular responses to chronic occupational stress. Understanding these mechanisms may provide a biologi-cal framework for resilience and wellbeing in clinical everyday practice. Objective: To narratively review the evidence linking oral cellular and molecular mechanisms, -salivary biomarkers, epithelial and immune cell activity, and microbiome dynamics- with stress, fatigue, burnout, and wellbeing outcomes among healthcare professionals. Methods: A PRISMA-guided search of PubMed, Scopus, Web of Science, and Cochrane Oral Health identified studies investigating oral cellular or molecular parameters in relation to occu-pational stress or wellbeing indicators in healthcare settings. Eligible designs included observational, experimental, and interventional studies. Data were extracted using stand-ardized forms, quality was appraised via ROBINS-I and the Newcastle-Ottawa scale, and results were synthesized thematically. Results: Evidence from 99 studies suggests that chronic occupational stress elevates salivary cortisol, oxidative stress markers, and pro-inflammatory cytokines (IL-6, TNF-α), while reducing protective salivary immuno-globulin A and microbiome diversity. Balanced oral immune and microbial profiles were associated with better psychological adaptation and lower fatigue indices. Conclusions: Oral cellular homeostasis offers a promising window into the biological underpinnings of occupational stress and resilience in healthcare professionals. Systematic integration of salivary and mucosal biomarkers into workplace wellbeing programs could enhance ear-ly detection of dysregulated stress physiology. Future interdisciplinary research should bridge oral biology, occupational medicine, and mental health to strengthen sustainable wellbeing strategies across the health workforce.