title: Difference in postprandial GLP-1 response despite similar glucose kinetics after consumption of wheat breads with different particle size in healthy men.
abstract: OBJECTIVE
  Underlying mechanisms of the beneficial health effects of low glycemic index starchy foods are not fully elucidated yet. We varied the wheat particle size to obtain fiber-rich breads with a high and low glycemic response and investigated the differences in postprandial glucose kinetics and metabolic response after their consumption.
  
  
  METHODS
  Ten healthy male volunteers participated in a randomized, crossover study, consuming13C-enriched breads with different structures; a control bread (CB) made from wheat flour combined with wheat bran, and a kernel bread (KB) where 85 % of flour was substituted with broken wheat kernels. The structure of the breads was characterized extensively. The use of stable isotopes enabled calculation of glucose kinetics: rate of appearance of exogenous glucose, endogenous glucose production, and glucose clearance rate. Additionally, postprandial plasma concentrations of glucose, insulin, glucagon, incretins, cholecystokinin, and bile acids were analyzed.
  
  
  RESULTS
  Despite the attempt to obtain a bread with a low glycemic response by replacing flour by broken kernels, the glycemic response and glucose kinetics were quite similar after consumption of CB and KB. Interestingly, the glucagon-like peptide-1 (GLP-1) response was much lower after KB compared to CB (iAUC, P < 0.005). A clear postprandial increase in plasma conjugated bile acids was observed after both meals.
  
  
  CONCLUSIONS
  Substitution of 85 % wheat flour by broken kernels in bread did not result in a difference in glucose response and kinetics, but in a pronounced difference in GLP-1 response. Thus, changing the processing conditions of wheat for baking bread can influence the metabolic response beyond glycemia and may therefore influence health.
authors: Center for Medical Biomics, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands. c.eelderink@umcg.nl.|Top Institute Food and Nutrition, Wageningen, The Netherlands. c.eelderink@umcg.nl.
authors: Coby
authors: C
authors: Eelderink
authors: TNO Food and Nutrition, Zeist, The Netherlands.
authors: Martijn W J
authors: MWJ
authors: Noort
authors: VTT Technical Research Centre of Finland, Espoo, Finland.
authors: Nesli
authors: N
authors: Sozer
authors: Department of Laboratory Medicine, Center for Liver Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors: Martijn
authors: M
authors: Koehorst
authors: NNF Center for Basic Metabolic Research, Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark.
authors: Jens J
authors: JJ
authors: Holst
authors: NNF Center for Basic Metabolic Research, Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark.
authors: Carolyn F
authors: CF
authors: Deacon
authors: Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors: Jens F
authors: JF
authors: Rehfeld
authors: VTT Technical Research Centre of Finland, Espoo, Finland.
authors: Kaisa
authors: K
authors: Poutanen
authors: Center for Medical Biomics, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
authors: Roel J
authors: RJ
authors: Vonk
authors: Top Institute Food and Nutrition, Wageningen, The Netherlands.|TNO Food and Nutrition, Zeist, The Netherlands.
authors: Lizette
authors: L
authors: Oudhuis
authors: Center for Medical Biomics, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.|Top Institute Food and Nutrition, Wageningen, The Netherlands.
authors: Marion G
authors: MG
authors: Priebe
mesh_terms: D001066:Appetite; D001647:Bile Acids and Salts / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D001939:Bread; D018592:Cross-Over Studies; D004043:Dietary Fiber / Q000008:administration & dosage; D005433:Flour; D005934:Glucagon / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D054795:Incretins / Q000097:blood; D007328:Insulin / Q000097:blood; D008297:Male; D010316:Particle Size; D019518:Postprandial Period; D014908:Triticum / Q000737:chemistry; D055815:Young Adult
chemical_list: D001647:Bile Acids and Salts; D001786:Blood Glucose; D004043:Dietary Fiber; D054795:Incretins; D007328:Insulin; D052216:Glucagon-Like Peptide 1; D005934:Glucagon
keywords: Bile acids; Bread processing; Glucagon-like peptide-1; Glucose kinetics; Glycemic index; Wheat kernels