Salivary volatilome profiling in pediatric eosinophilic esophagitis: a pilot study on a non-invasive approach in clinical practice

Eosinophilic esophagitis (EoE) is a chronic immune disease requiring repeated endoscopies for diagnosis and monitoring in children. Saliva represents a promising non-invasive biofluid, and volatile organic compounds (VOCs) may indicate disease presence and activity. This study aimed to examine the VOCs profile in saliva samples from children with EoE and to compare it with other gastrointestinal (GI) conditions and healthy controls. Thirty-five samples from children with EoE (including 13 active and 22 non-active cases), 19 from children with other GI conditions, and 46 from healthy controls were analyzed. Gas chromatography–ion mobility spectrometry (GC–IMS) identified 63 distinct VOC signal areas. The abundance of 16 of them was found significantly different (P < 0.01) in EoE vs. controls, EoE vs. other GI conditions, and active vs. non-active EoE. Among them, cis-3-hexen-1-ol and 2-phenylethanol show a ubiquitous capability to discriminate EoE against different populations. Linear discriminant analysis (LDA) of the panel of 16 VOCs achieved 83.3% accuracy in classifying EoE vs. healthy controls, 81.2% accuracy in distinguishing EoE from GI controls, and 80.0% accuracy in classifying active vs. non-active EoE. Salivary VOC profiling enables accurate discrimination of pediatric EoE from controls and stratification by disease activity. This non-invasive approach holds promise as a diagnostic and monitoring tool in clinical practice, especially in children.