Emulsion Stability Modulates Gastric Secretion and Its Mixing with Emulsified Fat in Healthy Adults in a Randomized Magnetic Resonance Imaging Study.
BACKGROUND
Oil-in-water emulsions have recently become of interest to nutritional sciences because of their ability to influence gastrointestinal digestive processes and ultimately benefit human health. MRI offers the potential to noninvasively characterize the interaction between emulsified lipids and gastric secretion within the stomach.


OBJECTIVE
We determined noninvasively how emulsion stability modulates volumes of fat and secretion, layering of fat, and the mixing of emulsified fat with secretion within the stomach. This required the development of MRI technology for quantifying fat and secretion concentrations inside the stomach.


METHODS
Twenty-one healthy adults [13 men, mean ± SD age: 22.5 ± 2.5 y, mean ± SD body mass index (in kg/m2): 22.7 ± 1.8] were analyzed in a single-blind, randomized, parallel design. MRI was used to acquire the distributions of fat and secretion in the stomach after ingestion of 2 emulsions: a stable emulsion (E1) or an unstable emulsion (E4) with 20% fat fraction and ∼0.3 mm droplet sizes. Layer, volume, and mixing variables were fitted to the data and compared between the 2 emulsions.


RESULTS
The intragastric mixing between fat and secretion was better with the E4 than the E1 [increase in content heterogeneity of 17.1% (95% CI: 12.3%, 21.9%)]. The E4 demonstrated a linear relation [slope 1.57 (95% CI: 0.86, 2.29)] between the degree of layering and mixing. In contrast, no such relation was detected for the E1. Accumulated secretion volume in the stomach was lower with the E4 [decrease in volume variable ksof 2.3 (95% CI: -3.9, -0.7)] and correlated with the degree of layering (r = 0.62, P < 0.001).


CONCLUSIONS
In healthy adults, intragastric fat layering was influenced mainly by the degree of intragastric mixing, rather than the overall dominance of secretion. The E1 triggered a higher accumulation of gastric secretion, which in turn facilitated homogenization of intragastric content in comparison with its unstable counterpart. This trial was registered at clinicaltrials.gov as NCT02602158.
Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; and.
Dian
http://orcid.org/0000-0002-3085-8767
D
Liu
Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
Helen L
HL
Parker
Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; and Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
Jelena
J
Curcic
Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; and.
Sebastian
S
Kozerke
Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; and Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland steingoetter@biomed.ee.ethz.ch.
Andreas
http://orcid.org/0000-0001-8046-1314
A
Steingoetter
D000328:Adult; D015992:Body Mass Index; D004041:Dietary Fats / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D004063:Digestion; D004655:Emulsions; D005260:Female; D005746:Gastric Emptying; D005753:Gastric Mucosa / Q000378:metabolism; D005766:Gastrointestinal Contents; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D016037:Single-Blind Method; D013270:Stomach / Q000000981:diagnostic imaging; D055815:Young Adult
D004041:Dietary Fats; D004655:Emulsions
fat quantification; gastric physiology; gastric secretion; gastrointestinal function; healthy adults; magnetic resonance imaging; oil-in-water emulsions