title: Ileal brake activation: macronutrient-specific effects on eating behavior?
abstract: BACKGROUND
  Activation of the ileal brake, by infusing lipid directly into the distal part of the small intestine, alters gastrointestinal (GI) motility and inhibits food intake. The ileal brake effect on eating behavior of the other macronutrients is currently unknown.
  
  
  OBJECTIVE
  The objective of this study was to investigate the effects of ileal infusion of sucrose and casein on food intake, release of GI peptides, gastric emptying rate and small-bowel transit time with safflower oil as positive control.
  
  
  METHODS
  This randomized, single-blind, crossover study was performed in 13 healthy subjects (6 male; mean age 26.4±2.9 years; mean body mass index 22.8±0.4 kg m(-2)) who were intubated with a naso-ileal catheter. Thirty minutes after the intake of a standardized breakfast, participants received an ileal infusion, containing control ((C) saline), safflower oil ((HL) 51.7 kcal), low-dose casein ((LP) 17.2 kcal) or high-dose casein ((HP) 51.7 kcal), low-dose sucrose ((LC) 17.2 kcal) and high-dose sucrose ((HC) 51.7 kcal), over a period of 90 min. Food intake was determined during an ad libitum meal. Visual analogue score questionnaires for hunger and satiety and blood samples were collected at regular intervals.
  
  
  RESULTS
  Ileal infusion of lipid, protein and carbohydrate resulted in a significant reduction in food intake compared with control (HL: 464.3±90.7 kcal, P<0.001; HP: 458.0±78.6 kcal, P<0.005; HC: 399.0±57.0 kcal, P<0.0001 vs control: 586.7±70.2 kcal, P<0.001, respectively). A reduction in energy intake was still apparent when the caloric amount of infused nutrients was added to the amount eaten during the ad libitum meal.Secretion of cholecystokinin and peptide YY but not of glucagon-like peptide-1 (7-36) was increased during ileal perfusion of fat, carbohydrates and protein. During ileal perfusion of all macronutrients, a delay in gastric emptying and intestinal transit was observed, but differences were not significant compared with control.
  
  
  CONCLUSIONS
  Apart from lipids, also sucrose and casein reduce food intake on ileal infusion, thereby activating the ileal brake. In addition to food intake, also satiety and GI peptide secretion were affected.
authors: 1] Top Institute of Food and Nutrition, Wageningen, The Netherlands [2] Division of Gastroenterology and Hepatology, Department of Internal Medicine, NUTRIM, Maastricht University Medical Center, Maastricht, The Netherlands.
authors: M
authors: M
authors: van Avesaat
authors: 1] Top Institute of Food and Nutrition, Wageningen, The Netherlands [2] Division of Gastroenterology and Hepatology, Department of Internal Medicine, NUTRIM, Maastricht University Medical Center, Maastricht, The Netherlands.
authors: F J
authors: FJ
authors: Troost
authors: 1] Top Institute of Food and Nutrition, Wageningen, The Netherlands [2] The Netherlands Organisation for Applied Scientific Research, TNO, Zeist, The Netherlands [3] Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
authors: D
authors: D
authors: Ripken
authors: 1] Top Institute of Food and Nutrition, Wageningen, The Netherlands [2] The Netherlands Organisation for Applied Scientific Research, TNO, Zeist, The Netherlands.
authors: H F
authors: HF
authors: Hendriks
authors: 1] Top Institute of Food and Nutrition, Wageningen, The Netherlands [2] Division of Gastroenterology and Hepatology, Department of Internal Medicine, NUTRIM, Maastricht University Medical Center, Maastricht, The Netherlands.
authors: A A M
authors: AA
authors: Masclee
mesh_terms: D000328:Adult; D002364:Caseins; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D064368:Healthy Volunteers / Q000706:statistics & numerical data*; D006801:Humans; D006815:Hunger / Q000187:drug effects; D007082:Ileum / Q000187:drug effects* / Q000503:physiopathology; D007260:Infusion Pumps; D008297:Male; D008875:Middle Aged; D012528:Satiety Response / Q000187:drug effects; D016037:Single-Blind Method; D013395:Sucrose; D016896:Treatment Outcome
chemical_list: D002364:Caseins; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D013395:Sucrose