Volatile organic compounds in exhaled breath as non-invasive biomarkers for Gastrointestinal motility disorders: an exploratory study

Background and aims Gastrointestinal (GI) motility disorders are characterized by abnormalities in the motor functions of the GI tract. The diagnostic evaluation of these disorders frequently involves invasive and time-consuming examinations, for which access may be limited. Volatile organic compounds (VOCs) could serve as non-invasive alternative. Therefore, the aim of this study was to explore the potential of exhaled breath VOCs as biomarkers in patients with GI symptoms and potential GI motility disorders. Methods In this exploratory, prospective study, breath samples were obtained from patients undergoing ambulatory motility tests as part of routine clinical care. VOCs in exhaled breath were assessed using thermal desorption chromatography-mass spectrometry (TD-GC-MS). The resulting data were subsequently pre-processed and analyzed using machine learning approaches. Results Hundred participants were included in the analysis, of whom 67 were women (67%), with a median age of 56.5 years (IQR: 29.8). The diagnostic work-up comprised 55 gastric emptying tests, 55 high-resolution esophageal manometries, 3 antroduodenal manometries, and 1 colon manometry. These examinations resulted in 48 motility disorder diagnoses, while 51 patients showed no evidence of motility abnormalities. Fifteen VOCs were identified as most discriminative markers for the presence or absence of GI dysmotility, with a sensitivity of 75%, and specificity of 60%. Conclusions VOCs in exhaled breath show promise to distinguish patients with GI motility disorders from those without, in a population of patients with GI symptoms. Future research is warranted to further refine and validate these results in a larger cohort and to explore the diagnostic performance of VOCs in specific subtypes of motility disorders.