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.