Xylose

The monosaccharides released during Butyrivibrio monoculture and coculture growth were determined using a HPIC method (55 ). Culture samples from the eight time intervals (0, 2, 4, 6, 8, 10, 12 and 16 h) were used for analysis, and the HPIC system used was the DIONEX ICS-5000 system (Thermo Fisher Scientific). Data analysis was performed with Chromeleon software (Thermo Fisher Scientific). Using a two-tailed, unpaired Student's t test, differences between sample means were considered statistically significant if the P value was <0.05. Quantitative analyses were carried out using standard solutions of the monosaccharides arabinose (Sigma-Aldrich), fucose (Sigma-Aldrich), galactose (Sigma-Aldrich), glucose (VWR International Ltd., Poole, UK), rhamnose (VWR), and xylose (VWR).

LC-MS-grade acetonitrile and ammonium acetate, as well as NH₃, were obtained from VWR (Vienna, Austria). Analytical-grade acarbose, arabinose, erythritol, fructose, galactose, glucose, inositol, lactitol, lactose, maltitol, raffinose, rhamnose, ribose, sucrose, xylitol, potassium chloride, ammonium iodide and potassium bromide were purchased from Sigma Aldrich (Schnelldorf, Germany). Erythrose, isomaltulose, lyxose, maltose, maltotriose, mannitol, mannose, sorbitol, sorbose, xylose, sodium nitrate and sodium sulfate were purchased from VWR (Vienna, Austria). LC-MS-grade water (< 0.055 µS cm⁻¹) from an ultrapure water purification system (Sartorius, Göttingen, Germany) was used for both elution and sample preparation. Food samples produced by various companies were obtained from local supermarkets. Sample matrices have been selected over a wide range of beverages and food to investigate the impact on sample preparation and robustness of the analytical method. Food and beverages were stored at the recommended temperature until analysis.