Oro-gastro-intestinal digestion of emulsified fat and how this digestion relates to colloidal stability and physiological responses

Interaction of fat with the mouth, stomach and intestines will trigger
physiological responses that will have impact on the (further) digestion, gut
transit time and absorption of the fat. Moreover, these responses will also
influence and contribute toward regulation of food intake and satiety.
No systematic research has been carried out on understanding how the
physicochemical properties of foods affect the digestion and absorption of
lipids. Previous studies have shown that the release of free fatty acids
triggers the fat-related physiological responses. We hypothesize that the
release of fatty acids is dependent of the colloidal state of the fat, which
changes progressively due to the pH-changes and enzymatic activities in the
mouth, stomach and intestines.

Primary Objective:
To determine oral, gastric and duodenal lipid degradation of fat preloads .

Secondary Objectives:
To study how the oro-gastro-intestinal digestion of these fat preloads relates
to:
- Colloidal stability. For this we will monitor changes in colloidal behaviour
(droplet size, flocculation, aggregation, coalescence) in samples from the
oral, gastric and duodenal compartment
- Physiological responses. For this, we will determine the gastric emptying
rate and small bowel transit time of the ingested emulsion systems. Furthermore
we will measure gallbladder motility and we will investigate the effect of the
ingested emulsion on food intake, postprandial satiety and hormone release.

Randomised single blinded cross over design

Application of a well- vs non-emulsified fat drink in the stomach or duodenum
or oral ingestion of the drink.

Subjects will have to undergo an overnight fasting period of 8 hours. This
implies no burden to the subject.
During the test day, insertion of the nasogastric duodenal feeding catheter
will take place. There is a very small risk of bowel perforation, but no
literature is available on the actual risk. This risk is generally considered
as nihil. The subjects will perceive mild discomfort during the placement of
the catheter. The radiation exposure during the positioning of the feeding tube
is minimal. The total exposure to radiation will be approximately 0.06 mSv,
which equals the radiation which is received during a one-hr flight in an
aeroplane at a 4-km altitude (www.nrg-nl.com).
The insertion of intravenous cannulae is a safe, routinely used technique in
daily clinical practice and could cause blue spots. Breath and saliva sampling
and echoscopy measurements are not associated with any risks