microbiota was allowed to adapt to the model conditions and SIEM for 16 h. After the adaptation period the 80 h test period started, in which test product were added to TIM- 2 in a daily dose. Administration of test product During the test period, the test product were added to the system in a daily dose. The test product were added to the system at the indicated dose in addition to the SIEM, which were added throughout the entire test period. The SIEM was added without carbohydrates, i.e. the test products replace the carbohydrates standard included in the SIEM during the experimental period. Since the test product are not digested in the small intestine, pre-digestion was performed. Sampling Samples were taken from the dialysis fluid (D in Figure 9) and from the lumen (G in Figure 9). Metabolites like short chain fatty acids (SCFA), branched-chain fatty acids (BCFA), and ammonia produced in TIM-2 are continuously removed from the lumen by a semipermeable membrane unit (D in Figure 9). This dialysate represents the amount available for absorption from the colon in vivo. The dialysate was collected after 8h and every 24 hours: t=0h, t=8h, t=32h, t=56h, t=80h after start of the test period. Volumes were measured and samples were taken from the dialysate (1 ml per analysis, 1 ml samples for back-up.) Luminal samples (in 1 ml aliquots) were collected via the sampling port (G in Figure 9) at the same time points (after 8h and every 24 hours) in order to determine the metabolite concentration in the lumen. In order to simulate the transit of the chime from proximal to distal colon, 25 ml (minus the ml used for sampling) of the lumen was removed after 8h and every 24 hours. Sample storage The samples were snap frozen in liquid nitrogen and stored at <-72°Cuntil analysis. Backup samples were taken of every time point and stored at <-72°Cuntil 1 month after submission of the final report.