The TIM-2 is the dynamic in vitro model of the large intestine. The conditions in the colon model are largely determined by the composition and density of the colon microbiota. To mimic the in vivo situation, before performing an experiment, the TIM-2 System is inoculated with a dense and highly metabolic active colon microbiota of human origin. Body temperature, pH in the lumen, delivery of a pre-digested substrate from the ‘ileum’ (SIEM: Standardized Ileal Effluent Medium), mixing and transport of the intestinal contents, absorption of water and metabolites (through dialysis) are simulated.
The content of TIM-2 is kept under strict anaerobic conditions, to optimally study fermentation and bioconversion of undigested compounds. Fermentation products and other low molecular weight compounds are continuously removed from the lumen via dialysis through a semipermeable membrane system inside the colon compartment. Samples can be taken from the dialyzed fraction as well as from the lumen.