title: Carbohydrate feeding dissociates the postprandial FGF19 response from circulating bile acid levels in humans.
abstract: BACKGROUND
  Fibroblast growth factor 19 (FGF19) improves glycemic control in diabetic animals and is secreted from the gastrointestinal tract after meals in response to bile acid stimulation.
  
  
  OBJECTIVE
  We sought to understand how ingestion of carbohydrates, protein or lipids affect both FGF19 and bile acid concentrations in human plasma, with the hypothesis that variation in the bile acid response to different macronutrients would predict differences in plasma FGF19 levels.
  
  
  METHODS
  This was a randomized, within-subjects crossover study.
  
  
  METHODS
  The study was conducted at a university clinical research center.
  
  
  METHODS
  There were 16 healthy human subjects included in the study.
  
  
  METHODS
  Isocaloric, isovolemic beverages composed primarily of carbohydrates, proteins, or lipids were provided to each participant on 3 separate occasions.
  
  
  METHODS
  The magnitudes of postprandial rises of plasma FGF19 and total bile acid levels were determined.
  
  
  RESULTS
  All beverages induced an initial transient decline of plasma FGF19 levels during the first 60 minutes after consumption. For FGF19, the ingestion of carbohydrate was associated with the fastest and highest increase of plasma levels, returning to baseline at 5 hours. By comparison, the protein beverage induced a modest but significant elevation of FGF19 levels that peaked at the end of the 6-hour sampling interval, whereas a lipid beverage was without effect. In contrast, total bile acid levels increased in plasma only in response to a high-lipid beverage, demonstrating a marked divergence between the FGF19 and bile acid response to lipid vs carbohydrate.
  
  
  CONCLUSIONS
  A bile acid-independent mechanism is implicated in the effect of meals to raise plasma FGF19 concentrations.
authors.affiliation: Department of Medicine (G.J.M., K.E.F.-S., D.E.C., M.W.S.) and Department of Dental Public Health Sciences (K.J.K.), School of Dentistry, University of Washington, Seattle, Washington 98195; and Veterans Affairs Puget Sound Health Care System (K.E.F.-S., D.E.C.), Seattle, Washington 98108.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Morton
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Kaiyala
authors.forename: Karen E
authors.initials: KE
authors.lastname: Foster-Schubert
authors.forename: David E
authors.initials: DE
authors.lastname: Cummings
authors.forename: Michael W
authors.initials: MW
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D000368:Aged; D001647:Bile Acids and Salts / Q000097:blood*; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates; D005260:Female; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period / Q000502:physiology*
chemical_list: D001647:Bile Acids and Salts; D004040:Dietary Carbohydrates; C117476:FGF19 protein, human; D005346:Fibroblast Growth Factors