Periodontitis biomarkers through thermal desorption-gas chromatography-mass spectrometry analysis.

BACKGROUND

Periodontitis is a growing public health concern worldwide. Salivary volatile metabolites have emerged as promising biomarkers for the diagnosis of periodontal disease. However, research on the collection and identification of these metabolites in periodontitis patients remains limited.

OBJECTIVES

To explore methods for collecting and identifying salivary volatile metabolites in periodontitis patients and investigate their potential as biomarkers for diagnosing periodontal disease.

METHOD: Oral exhaled breath and saliva samples were collected from 115 periodontitis patients and 35 healthy individuals, divided into four cohorts. The discovery cohort (Periodontitis: P = 55, Healthy: H = 23) and the test cohort (P = 48, H = 23) were screened and validated for potential biomarkers in volatile metabolites from oral exhaled breath by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The validation cohort 1 (P = 12, H = 12) was tested for volatile metabolites in saliva by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS), while validation cohort 2 (P = 55, H = 23) was tested for metabolic pathways in saliva by liquid chromatography-mass spectrometry (LC-MS).

RESULT: A total of 78 Volatile organic compounds (VOCs) were detected by TD-GC-MS, with 14 differential VOCs identified. A diagnostic model was established using cyclohexanone, styrene, and ethanol, yielding a combined AUC of 0.8237. These metabolites were also detected in saliva by SPME-GC-MS, with cyclohexanone showing higher expression in the periodontitis group (P < 0.05). The caprolactam degradation pathway was a key source of volatile metabolites in the oral exhaled breath of periodontitis patients.

CONCLUSION

We developed a novel method for analyzing salivary volatile metabolites using TD-GC-MS, demonstrating potential for periodontitis diagnosis. Cyclohexanone is identified as a potential biomarker for periodontitis, and the caprolactam degradation pathway may play a significant role in future studies on oral microbiota dysbiosis in periodontitis patients.