title: The impact of Roux-en-Y gastric bypass surgery on normal metabolism in a porcine model.
abstract: BACKGROUND
  A growing body of literature on Roux-en-Y gastric bypass surgery (RYGB) has generated inconclusive results on the mechanism underlying the beneficial effects on weight loss and glycaemia, partially due to the problems of designing clinical studies with the appropriate controls. Moreover, RYGB is only performed in obese individuals, in whom metabolism is perturbed and not completely understood.
  
  
  METHODS
  In an attempt to isolate the effects of RYGB and its effects on normal metabolism, we investigated the effect of RYGB in lean pigs, using sham-operated pair-fed pigs as controls. Two weeks post-surgery, pigs were subjected to an intravenous glucose tolerance test (IVGTT) and circulating metabolites, hormones and lipids measured. Bile acid composition was profiled after extraction from blood, faeces and the gallbladder.
  
  
  RESULTS
  A similar weight development in both groups of pigs validated our experimental model. Despite similar changes in fasting insulin, RYGB-pigs had lower fasting glucose levels. During an IVGTT RYGB-pigs had higher insulin and lower glucose levels. VLDL and IDL were lower in RYGB- than in sham-pigs. RYGB-pigs had increased levels of most amino acids, including branched-chain amino acids, but these were more efficiently suppressed by glucose. Levels of bile acids in the gallbladder were higher, whereas plasma and faecal bile acid levels were lower in RYGB- than in sham-pigs.
  
  
  CONCLUSIONS
  In a lean model RYGB caused lower plasma lipid and bile acid levels, which were compensated for by increased plasma amino acids, suggesting a switch from lipid to protein metabolism during fasting in the immediate postoperative period.
authors.affiliation: Neuroendocrine Cell Biology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Malmö, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lindqvist
authors.affiliation: Department of Surgery, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Ekelund
authors.affiliation: Vascular ET-coupling, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Malmö, Sweden.
authors.forename: Eliana
authors.initials: E
authors.lastname: Garcia-Vaz
authors.affiliation: Sahlgrenska Academy, Institute of Medicine, Department of Molecular and Clinical Medicine and Wallenberg Laboratory, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Marcus
authors.initials: M
authors.lastname: Ståhlman
authors.affiliation: Department of Cell and Organism Biology, Lund University, Lund, Sweden.|Innovation Center STB, Tczew, Poland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Pierzynowski
authors.affiliation: Vascular ET-coupling, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Malmö, Sweden.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Gomez
authors.affiliation: Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jens F
authors.initials: JF
authors.lastname: Rehfeld
authors.affiliation: Diabetes and Endocrinology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Malmö, Sweden.
authors.forename: Leif
authors.initials: L
authors.lastname: Groop
authors.affiliation: Neuroendocrine Cell Biology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Malmö, Sweden.|Surgery, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Hedenbro
authors.affiliation: Neuroendocrine Cell Biology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Malmö, Sweden.
authors.forename: Nils
authors.initials: N
authors.lastname: Wierup
authors.affiliation: Molecular Metabolism, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Malmö, Sweden.|Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Lund, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Spégel
mesh_terms: D000818:Animals; D001786:Blood Glucose; D004195:Disease Models, Animal; D005215:Fasting / Q000097:blood; D015390:Gastric Bypass / Q000009:adverse effects*; D005947:Glucose / Q000378:metabolism; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D009765:Obesity / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery*; D013552:Swine; D015431:Weight Loss / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose