Serum amyloid A in the oral microenvironment: implications for inflammation, host-microbe interactions, and disease...

To summarize current evidence regarding the role of serum amyloid A (SAA) in the oral microenvironment, with particular focus on its involvement in oral inflammation, host-microbe interactions, biofilm-associated chronic inflammation, and its potential utility as a diagnostic biomarker.

Relevant literature regarding SAA in oral inflammation, host-microbe interactions, oral carcinogenesis, and salivary diagnostics was reviewed and synthesized. Particular emphasis was placed on studies investigating oral pathogens, inflammatory signaling pathways, biofilm-associated inflammation, salivary diagnostics, and veterinary applications of salivary SAA monitoring.

Accumulating evidence indicates that SAA is not only a classical acute-phase protein but also an active regulator of inflammatory responses. In the oral cavity, pathogenic microorganisms and persistent biofilm-associated stimulation can induce local and systemic SAA expression through innate immune signaling pathways, including TLR2/TLR4 and NF-κB signaling. SAA contributes to neutrophil recruitment, macrophage activation, cytokine amplification, and maintenance of chronic inflammatory microenvironments. Emerging studies further suggest that SAA may participate in biofilm-associated inflammatory persistence and may contribute to tissue remodeling and disease progression. In addition, SAA can be detected in saliva and inflammatory oral fluids, highlighting its potential as a non-invasive biomarker for disease monitoring. Veterinary studies investigating salivary SAA further support the feasibility of continuous and minimally invasive inflammatory monitoring.

SAA represents an important molecular link between oral microbial dysbiosis, chronic inflammation, and disease progression within the oral microenvironment. Beyond its role as a systemic inflammatory marker, SAA actively participates in immune regulation and host-microbe interactions. Salivary SAA monitoring may provide a promising non-invasive approach for longitudinal assessment of oral inflammatory diseases and related pathological conditions.