Gastrointestinal metabolism of a vegetable-oil emulsion in healthy subjects.
BACKGROUND
Given the growing prevalence of overweight and obesity, weight-management strategies could be developed based on the effect of specific food ingredients on the gastrointestinal system to reduce food intake.


OBJECTIVE
The aim of this study was to investigate the mechanisms by which a vegetable-oil emulsion may exert its effect on satiety by applying a multilumen tube to investigate digestion and absorption of lipids in the stomach and proximal jejunum.


METHODS
We gave 16 healthy, normal-weight subjects (in a double-blind, placebo-controlled crossover design) a test product (yogurt with a vegetable-oil emulsion) or an equal-calorie control by intragastric administration on 2 separate occasions. Gastric and intestinal samples were collected from the proximal jejunum during 180 min.


RESULTS
We observed almost double amounts (P < 0.05) of total lipids, mainly as free fatty acids, from the test product (450 +/- 119 mg) in the proximal jejunum compared with amounts of total lipids from the control product (230 +/- 50 mg), and an over-time difference of free fatty acid concentrations was observed between the products (P < 0.05). To our knowledge, a novel and unexpected finding was the appearance of needle-shaped crystals in the jejunal samples that originated from the vegetable-oil emulsion and consisted of saturated fatty acids. Crystals were only rarely seen in the control samples.


CONCLUSIONS
The higher amount of lipids in the proximal jejunum and the recovery of crystals in the intestinal samples after test-product infusion provide a plausible physiologic explanation for the ileal brake mechanism that leads to the increased satiety observed for this test product.
Knutson
Lars
L
Departments of Surgical Sciences, Uppsala University, Sweden. lars.knutson@surgsci.uu.se
Koenders
Damiet J P C
DJ
Fridblom
Helle
H
Viberg
Annika
A
Sein
Arjen
A
Lennernäs
Hans
H
D000328:Adult; D018592:Cross-Over Studies; D003460:Crystallization; D004041:Dietary Fats / Q000008:administration & dosage*; D004063:Digestion; D004311:Double-Blind Method; D004655:Emulsions; D005227:Fatty Acids / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology; D006801:Humans; D007408:Intestinal Absorption; D007583:Jejunum / Q000378:metabolism*; D050356:Lipid Metabolism; D008297:Male; D009765:Obesity / Q000517:prevention & control; D010938:Plant Oils / Q000378:metabolism* / Q000494:pharmacology; D012016:Reference Values; D012527:Satiation / Q000187:drug effects / Q000502:physiology*; D015014:Yogurt; D055815:Young Adult
D004041:Dietary Fats; D004655:Emulsions; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D010938:Plant Oils