The droplet size of intraduodenal fat emulsions influences antropyloroduodenal motility, hormone release, and appetite in healthy males.
BACKGROUND
The presence of fat in the small intestine modulates gastrointestinal motility, stimulates plasma cholecystokinin and peptide YY release, and suppresses appetite and energy intake. These effects are dependent on the lipolysis of fat.


OBJECTIVE
Our aim was to evaluate the hypothesis that increasing the droplet size of a fat emulsion would attenuate these effects.


METHODS
Ten healthy, lean males were studied on 4 separate occasions in single-blind randomized order. Antropyloroduodenal pressures, plasma triglycerides, cholecystokinin, peptide YY, and appetite were measured during 120-min intraduodenal infusions of fat emulsions comprising 3 different droplet sizes: 1) 0.26 microm (LE-0.26), 2) 30 microm (LE-30), and 3) 170 microm (LE-170) in addition to saline (control). Energy intake at a buffet lunch was quantified immediately after the infusions.


RESULTS
Increasing the droplet size of the lipid emulsion was associated with diminished suppression of antral (r = 0.75, P < 0.01) and duodenal (r = 0.80, P < 0.01) pressure waves and with stimulation of isolated (r = -0.72, P < 0.01) and basal (r = -0.83, P < 0.01) pyloric pressures. Increasing the droplet size was also associated with attenuation of the stimulation of plasma triglycerides (r = -0.73, P < 0.001), cholecystokinin (r = -0.73, P < 0.001), and peptide YY (r = -0.83, P < 0.001) as well as with reductions in the suppression of hunger (r = 0.75, P < 0.01) and energy intake (r = 0.66, P < 0.001).


CONCLUSIONS
The acute effects of intraduodenal fat emulsions on gastrointestinal function and appetite are dependent on fat droplet size. These observations have implications for the design of functional foods to maximize effects on those gut functions that are involved in the suppression of appetite.
University of Adelaide Discipline of Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.
Radhika V
RV
Seimon
Timothy
T
Wooster
Bärbel
B
Otto
Matthew
M
Golding
Li
L
Day
Tanya J
TJ
Little
Michael
M
Horowitz
Peter M
PM
Clifton
Christine
C
Feinle-Bisset
D001066:Appetite / Q000187:drug effects*; D019540:Area Under Curve; D002766:Cholecystokinin / Q000097:blood / Q000378:metabolism*; D004041:Dietary Fats / Q000008:administration & dosage; D004386:Duodenum / Q000187:drug effects / Q000502:physiology; D004655:Emulsions; D002149:Energy Intake / Q000187:drug effects*; D005223:Fats / Q000008:administration & dosage / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D006815:Hunger / Q000187:drug effects; D008297:Male; D008365:Manometry; D009325:Nausea; D010316:Particle Size; D019894:Peptide YY / Q000097:blood / Q000378:metabolism*; D011312:Pressure; D011708:Pylorus / Q000187:drug effects / Q000502:physiology; D012527:Satiation / Q000187:drug effects; D016037:Single-Blind Method; D014280:Triglycerides / Q000097:blood*
D004041:Dietary Fats; D004655:Emulsions; D005223:Fats; D014280:Triglycerides; D019894:Peptide YY; D002766:Cholecystokinin