title: Imaging gastric structuring of lipid emulsions and its effect on gastrointestinal function: a randomized trial in healthy subjects.
abstract: BACKGROUND
  Efficient fat digestion requires fat processing within the stomach and fat sensing in the intestine. Both processes also control gastric emptying and gastrointestinal secretions.
  
  
  OBJECTIVE
  We aimed to visualize the influence of the intragastric stability of fat emulsions on their dynamics of gastric processing and structuring and to assess the effect this has on gastrointestinal motor and secretory functions.
  
  
  METHODS
  Eighteen healthy subjects with normal body mass index (BMI) were studied on 4 separate occasions in a double-blind, randomized, crossover design. Magnetic resonance imaging (MRI) data of the gastrointestinal tract and blood triglycerides were recorded before and for 240 min after the consumption of the following 4 different fat emulsions: lipid emulsion 1 (LE1; acid stable, 0.33 μm), lipid emulsion 2 (LE2; acid stable, 52 μm), lipid emulsion 3 (LE3; acid unstable, solid fat, 0.32 μm), and lipid emulsion 4 (LE4; acid unstable, liquid fat, 0.38 μm).
  
  
  RESULTS
  Intragastric emulsion instability was associated with a change in gastric emptying. Acid-unstable emulsions exhibited biphasic and faster emptying profiles than did the 2 acid-stable emulsions (P ≤ 0.0001). When combined with solid fat (LE3), different dynamics of postprandial gallbladder volume were induced (P ≤ 0.001). For acid-stable emulsions, a reduction of droplet size by 2 orders of magnitude [LE1 (0.33 μm) compared with LE2 (52 μm)] delayed gastric emptying by 38 min. Although acid-stable (LE1 and LE2) and redispersible (LE4) emulsions caused a constant increase in blood triglycerides, no increase was detectable for LE3 (P < 0.0001). For LE3, MRI confirmed the generation of large fat particles during gastric processing, which emptied into and progressed through the small intestine.
  
  
  CONCLUSIONS
  MRI allows the detailed characterization of the in vivo fate of lipid emulsions. The acute effects of lipid emulsions on gastric emptying, gallbladder volume, and triglyceride absorption are dependent on microstructural changes undergone during consumption. Gastric peristalsis and secretion were effective at redispersing pools of liquid fat in the stomach. This trial was registered at clinicaltrials.gov as NCT01253005.
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Andreas
authors.initials: A
authors.lastname: Steingoetter
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Tijana
authors.initials: T
authors.lastname: Radovic
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Simon
authors.initials: S
authors.lastname: Buetikofer
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Jelena
authors.initials: J
authors.lastname: Curcic
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Dieter
authors.initials: D
authors.lastname: Menne
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Michael
authors.initials: M
authors.lastname: Fried
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Werner
authors.initials: W
authors.lastname: Schwizer
authors.affiliation: From the Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland (AS, TR, SB, JC, MF, and WS); the Institute for Biomedical Engineering, University and Federal Institute of Technology Zurich, Zurich, Switzerland (AS); Menne Biomed Consulting, Tübingen, Germany (DM); the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Preventive Health Flagship, Werribee, Australia (TJW); and the Nestlé Research Centre, Vers Chez les Blancs, Switzerland (TJW).
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Wooster
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D018592:Cross-Over Studies; D004063:Digestion / Q000502:physiology*; D004311:Double-Blind Method; D004655:Emulsions / Q000737:chemistry*; D005260:Female; D005746:Gastric Emptying; D064368:Healthy Volunteers; D006801:Humans; D008055:Lipids / Q000097:blood*; D008279:Magnetic Resonance Imaging; D008297:Male; D019518:Postprandial Period; D013270:Stomach / Q000502:physiology*; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D004655:Emulsions; D008055:Lipids; D014280:Triglycerides
keywords: acid stability; fat digestion; gastrointestinal function; lipid emulsion; magnetic resonance imaging