Duodenal and ileal nutrient deliveries regulate human intestinal motor and pancreatic responses to a meal

It is assumed that in humans pancreatic and gastrointestinal motor responses to a meal are coordinated and regulated mainly by duodenal nutrient exposure. On the other hand, there is evidence that the distal intestine may participate in the regulation of gastrointestinal functions. The aim of this study was to compare human pancreatic and intestinal motility responses to a meal and to correlate them with nutrient exposure of the proximal and distal intestine. After intubation with an oroileal multilumen tube for marker perfusion, duodenal and ileal aspiration, and intestinal manometry, 14 healthy subjects received a mixed test meal (1,257 kJ). Intraluminal nutrient concentrations, enzyme activities, and small intestinal motility were analyzed for 6 h postprandially. Duration of duodenal nutrient exposure was 3.4 +/- 0.2 h, and duration of pancreatic enzyme response and fed motor pattern was 2.5 +/- 0.2 and 3.5 +/- 0.3 h, respectively. Durations of pancreatic secretory and motor responses were correlated (P < 0.05), but neither duration of digestive secretory nor of motor activity correlated with that of prandial duodenal nutrient concentrations. By contrast, they were associated with the relative increase in ileal nutrient delivery late postprandially (P < 0.05). Physiological late postprandial delivery of nutrients to distal intestinal sites is correlated with the termination of digestive pancreatic and motor responses and may participate in their control.