Breath Volatile Organic Compounds as Non‐Invasive Tools for the Detection and Monitoring of Inflammatory Bowel Disease

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) diagnosis and disease evaluation require endoscopy, histology, or radiology, which are often invasive or expensive. A non-invasive diagnostic method is urgently needed. The present study examined the utility of volatile organic compounds (VOCs) to distinguish IBD from normal controls and monitor disease progression. METHODS: Breath samples were collected from 98 IBD patients, 77 non-IBD controls, and 8 non-IBD enteritis. VOCs were extracted using the solid phase microextraction (SPME) technique and detected using high-resolution gas chromatography-mass spectrometry (GC-MS). Four machine learning models were used in our study. Feature VOCs were those differentially presented in all these four models for diagnosis when compared patients with IBD and non-IBD controls. The performance of the VOC panels in the best selected model was carried out in a training set and confirmed in a validation set and testing set. RESULTS: A total of seven VOCs were selected for the diagnosis of IBD. The Random Forest model showed distinct differentiation between IBD patients and the non-IBD controls in the training set (AUC: 1.000 [1.000, 1.000]), validation set (AUC: 0.978 [0.978, 0.978]) and testing set (AUC: 0.966 [0.906, 1.000]). Among them, four VOCs were found to be related to IBD activity. CONCLUSIONS: Breath VOCs appeared to be useful tools for the diagnosis and activity monitoring of IBD patients.