Volatile metabolites in breath strongly correlate with gut microbiome in CD patients

Although profiles of both gut microbiota and exhaled volatile metabolites have been associated with gastrointestinal diseases, a direct link between them has not yet been investigated. From 68 CD patients a total of 184 repeated faecal and breath samples were collected (92 during active disease and 92 during quiescent disease). The microbiota composition was assessed by pyrosequencing of the 16S rRNA V1-V3 gene region. Volatile metabolites in breath were detected by gas chromatography-time-of-flight mass spectrometry. This is the first study that shows a strong relation between profiles of volatile metabolites in exhaled air with the intestinal microbiota, and was found to differ between active and quiescent CD indicating various underlying mechanisms.