Fig. 1. The TNO intestinal model (TIM). (1) The gastric compartment, comprising two glass units with interior flexible walls, surrounded by water at 37°C; (2) the persitaltic movements of the gastric wall are simulated; (3) secretion of gastric acid, electrolytes and enzymes (pepsinogen/pepsine, lipase); (4) pH electrode to control gastric pH; (5) simulated pyloric sphincter, regulating the delivery of gastric contents into the duodenum; (6) duodenal compartment with simulated peristaltic movements (see Supplemental data); (7) pH electrode to control the duodenal pH by the secretion of bicarbonate; (8) secretion of duodenal electrolytes, bile and pancreatic enzymes; (9) jejunal compartment with simulation of the peristaltic movements (see Supplemental data); (10) pH electrode to control the jejunal pH value by the secretion of bicarbonate; (11) ileal compartment with simulation of the peristaltic movements; (12) pH electrode to control the ileal pH value by the secretion of bicarbonate; (13) simulated ileo-caecal valve, regulating the delivery of ileal contents into the large intestine, mimicking the intestinal passage; (14) prefilter system; and (15) semipermeable membrane unit (hollow fibers) for absorption of digested products and water.