title: Effects of different sweet preloads on incretin hormone secretion, gastric emptying, and postprandial glycemia in healthy humans.
abstract: BACKGROUND
  Macronutrient "preloads" can stimulate glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), slow gastric emptying, and reduce postprandial glycemic excursions. After sweet preloads, these effects may be signaled by sodium-glucose cotransporter-1 (SGLT1), sweet taste receptors, or both.
  
  
  OBJECTIVE
  We determined the effects of 4 sweet preloads on GIP and GLP-1 release, gastric emptying, and postprandial glycemia.
  
  
  METHODS
  Ten healthy subjects were studied on 4 separate occasions each. A preload drink containing 40 g glucose, 40 g tagatose/isomalt mixture (TIM), 40 g 3-O-methylglucose (3OMG; a nonmetabolized substrate of SGLT1), or 60 mg sucralose was consumed 15 min before a (13)C-octanoic acid-labeled mashed potato meal. Blood glucose, plasma total GLP-1 and GIP, serum insulin, and gastric emptying were determined.
  
  
  RESULTS
  Both glucose and 3OMG stimulated GLP-1 and GIP release in advance of the meal (each P < 0.05), whereas TIM and sucralose did not. The overall postprandial GLP-1 response was greater after glucose, 3OMG, and TIM than after sucralose (P < 0.05), albeit later after TIM than the other preloads. The blood glucose and insulin responses in the first 30 min after the meal were greatest after glucose (each P < 0.05). Gastric emptying was slower after both 3OMG and TIM than after sucralose (each P < 0.05).
  
  
  CONCLUSIONS
  In healthy humans, SGLT1 substrates stimulate GLP-1 and GIP and slow gastric emptying, regardless of whether they are metabolized, whereas the artificial sweetener sucralose does not. Poorly absorbed sweet tastants (TIM), which probably expose a greater length of gut to nutrients, result in delayed GLP-1 secretion but not in delayed GIP release. These observations have the potential to optimize the use of preloads for glycemic control. This trial was registered at www.actr.org.au as ACTRN12611000775910.
authors.affiliation: Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Australia.
authors.forename: Tongzhi
authors.initials: T
authors.lastname: Wu
authors.forename: Beiyi R
authors.initials: BR
authors.lastname: Zhao
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Bound
authors.forename: Helen L
authors.initials: HL
authors.lastname: Checklin
authors.forename: Max
authors.initials: M
authors.lastname: Bellon
authors.forename: Tanya J
authors.initials: TJ
authors.lastname: Little
authors.forename: Richard L
authors.initials: RL
authors.lastname: Young
authors.forename: Karen L
authors.initials: KL
authors.lastname: Jones
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Rayner
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D019422:Dietary Sucrose / Q000008:administration & dosage / Q000494:pharmacology*; D004187:Disaccharides / Q000494:pharmacology; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects*; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D006601:Hexoses / Q000494:pharmacology; D006801:Humans; D054795:Incretins / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism; D008297:Male; D019518:Postprandial Period; D015398:Signal Transduction / Q000187:drug effects; D051269:Sodium-Glucose Transporter 1 / Q000378:metabolism; D013395:Sucrose / Q000031:analogs & derivatives / Q000494:pharmacology; D013402:Sugar Alcohols / Q000494:pharmacology; D013549:Sweetening Agents / Q000008:administration & dosage / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D019422:Dietary Sucrose; D004187:Disaccharides; D006601:Hexoses; D054795:Incretins; D007328:Insulin; C495674:SLC5A1 protein, human; D051269:Sodium-Glucose Transporter 1; D013402:Sugar Alcohols; D013549:Sweetening Agents; D013395:Sucrose; D005749:Gastric Inhibitory Polypeptide; C016640:Palatinit; D052216:Glucagon-Like Peptide 1; C026285:trichlorosucrose; D005947:Glucose; C030192:tagatose