Gastrointestinal metabolism of a vegetable-oil emulsion in healthy subjects

• Published in: The American journal of clinical nutrition Vol. 92; no. 3; pp. 515 - 524
• Main Authors: Knutson, Lars, Koenders, Damiet JPC, Fridblom, Helle, Viberg, Annika, Sein, Arjen, Lennernäs, Hans
• Format: Journal Article
• Language: English
• Published: United States American Society for Clinical Nutrition 01.09.2010; American Society for Clinical Nutrition, Inc
• Subjects: administration & dosage; Adult; adults; Cross-Over Studies; Crystallization; crystals; Diet; Dietary Fats; Dietary Fats - administration & dosage; digesta; Digestion; Digestive system; Double-Blind Method; drug effects; Emulsions; Fatty Acids; Fatty Acids - metabolism; Fatty Acids, Nonesterified; Fatty Acids, Nonesterified - metabolism; Female; food intake; free fatty acids; functional foods; Gastrointestinal Transit; Gastrointestinal Transit - physiology; Humans; ileal brake; ileum; Intestinal Absorption; jejunum; Jejunum - metabolism; Lipid Metabolism; Lipids; Male; MEDICIN; MEDICINE; Metabolism; Nutrition; Obesity; Obesity - prevention & control; pharmacology; physiology; Plant Oils; Plant Oils - metabolism; Plant Oils - pharmacology; prevention & control; Reference Values; Satiation; Satiation - drug effects; Satiation - physiology; satiety; saturated fatty acids; stomach; vegetable oil; Vegetable oils; Weight control; Yogurt; Young Adult
• DOI: 10.3945/ajcn.2009.28941
• ISSN: 0002-9165; 1938-3207

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. DESIGN: 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. CONCLUSION: 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.