Salivary short chain fatty acids serve as biomarkers of periodontal inflammatory burden

Periodontitis is a chronic inflammatory condition associated with systemic diseases. Early detection and intervention are crucial; however, conventional diagnostic methods require specialized dental procedures. Therefore, we aimed to develop a noninvasive saliva-based screening method that can be easily performed outside dental clinics. This cross-sectional pilot study evaluated three periodontal indices-probing depth, Periodontal Inflamed Surface Area (PISA), and periodontal epithelial surface area-in relation to short-chain fatty acids (SCFAs) and bacterial profiles in the saliva. Saliva samples collected during the day exhibited stronger correlations with periodontal indices than waking time samples, demonstrating a significant association with periodontal pathogens, protease activity, and elevated levels of butyric acid. The diagnostic thresholds for PISA were 300 mm² and 600 mm². Multivariate logistic regression and likelihood ratio analyses identified the combination of enzymatic SCFA markers and dipstick-based occult blood or leukocyte detection as a promising biomarker pair. Combining enzymatic SCFA markers with occult blood demonstrated a positive likelihood ratio of 3.4 and a negative likelihood ratio of 0.19 for PISA ≥ 600 mm², with a post-test probability of 77%, sensitivity of 86%, and specificity of 75%. These findings suggest that combining salivary enzymatic and dipstick-based biomarkers provides a simple, cost-effective, and moderately informative screening strategy for periodontitis.