Background: Exhaled breath analysis using an e-nose is a groundbreaking tool for exhaled volatile organic compound (VOC) analysis, which has already shown its conceivability in several respiratory and systemic diseases. It is still unclear whether food intake can be considered a confounder when analyzing the VOC-profile. We aimed to assess whether an e-nose can discriminate exhaled breath before and after predefined food intake at different time periods.
Methods: We enrolled 20 healthy non-smoking adults and collected their exhaled breath as follows: (a) before food intake, (b) within 5 min after food consumption, (c) within 1 hour after eating, and (d) within 2 hours after eating. Exhaled breath was collected by a formerly validated method and analyzed by an e-nose (Cyranose 320).
Results: By principal component analysis, significant variations in the exhaled VOC profile were shown for principal component 1 (capturing 63.4% of total variance) when comparing baseline vs 5 minutes and vs 1 hour after food intake (p<0.05 for both analyses).  No significance was shown in the comparison between baseline and 2 hours after food intake (p=ns).   
Conclusions: The exhaled VOC profile seems to be influenced by very recent food intake. Interestingly, two hours might be sufficient to avoid food induced alterations of exhaled VOCs spectrum when sampling for research protocols.