The aim of this study was to identify probable intermediate biomarkers of disturbed pathways and their link between smoking. Methods Un-stimulated whole saliva and serum samples were collected from a total of 30 systemically healthy participants with periodontally healthy smokers (S) (n=15) and nonsmokers (n=15). Periodontal indices (plaque index, gingival index, probing depth, bleeding on probing, clinical attachment level) were recorded to confirm periodontal health. Saliva was purified, and a total of 28 amino acids and metabolites were analyzed by liquid chromatographymass spectrometry (LC-MS/MS). Smoking status was validated measuring serum cotinine levels. Intergroup comparisons were assessed using the Mann Whitney U test. Results When 28 amino acids were evaluated, smokers had statistically significantly higher cystathionine levels than non-smokers (p <0.05). Conclusions Saliva cystathionine is associated with smoking in periodontally healthy individuals, and is possibly related to altered sulfuration pathway.

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