Dietary fiber (DF) when fermented, produces a variety of bioactive metabolites. These volatile compounds exit the body through the breath. A study was set out to analyze breath volatile metabolites (BVM) after taking maltodextrin (placebo) and then, chitin-glucan. They found that maltodextrin had no results, while the chitin-glucan showed an increase in exhaled volatile metabolites. It analyzed the profile of exhaled breath volatile metabolites (BVM) and gastrointestinal symptoms in healthy volunteers after a single ingestion of maltodextrin (placebo) versus chitin-glucan (CG), which ferments into short-chain fatty acids (SCFA) by the human microbiota. A standardized breakfast was given to fasting healthy individuals (n=15) with maltodextrin (4.5 g at day 0) or CG (4.5 g at day 2). Throughout the day, selected ion flow tube mass spectrometry (SIFT-MS) was used to assess BVM. 4.5 g CG did not cause significant gastrointestinal discomfort after a single intake. An untargeted metabolomics study of breath has highlighted that 13 MS-fragments (among 408 ionized molecules of breath) were able to tell between CG and maltodextrin ingestion in the postprandial state. The study found that after ingestion of CG, it increased exhaled butyrate and five other BVM, including 2,3-butanedione and 3-hydroxybutanone to a maximum at 6 h. The concentration of Mitsuokella in breath samples correlates with the presence of butyric acid, triethylamine, and 3-hydroxybutanone. The concentration of Mitsuokella in breath samples correlates with the presence of butyric acid, triethylamine, and 3-hydroxybutanone. Finally, measuring BMV in the breath reveals the bacterial signature of DF fermentation after a single intake. This method may be used to study the time-course of produced bioactive molecules, which could potentially be associated with biological properties, as part of this study.