Effects of dietary lipid composition and inulin-type fructans on mineral bioavailability in growing rats

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Los Angeles County, Calif.), 2009-02, Vol.25 (2), p.216-225
• Main Authors: Lobo, Alexandre Rodrigues, M.Sc, Filho, Jorge Mancini, Ph.D, Alvares, Eliana Parisi, Ph.D, Cocato, Maria Lucia, M.Sc, Colli, Célia, Ph.D
• Format: Article
• Language: English
• Subjects: animal models; Animals; Atomic absorption spectrophotometry; Bioavailability; Biological and medical sciences; Biological Availability; Biomechanics; Bone and Bones - drug effects; Bone and Bones - metabolism; Cecum - drug effects; Cecum - metabolism; Diet; dietary fat; Dietary Fats - pharmacology; Dietary Fats, Unsaturated - pharmacology; Dietary minerals; experimental diets; fat intake; Fatty acids; Feces - chemistry; Feeding. Feeding behavior; Fish oil; Fish oils; Fish Oils - pharmacology; Food; fructans; Fructans - pharmacology; Fundamental and applied biological sciences. Psychology; Gastroenterology and Hepatology; Gene expression; growth and development; Intestinal Absorption - drug effects; inulin; Inulin - pharmacology; Inulin-type fructans; lipid composition; Lipids; Magnesium; Male; Mineral absorption; Minerals - pharmacokinetics; Minerals - urine; nutrient availability; nutrition physiology; Pharmaceutical sciences; Polyunsaturated fatty acids; Random Allocation; Rats; Rats, Wistar; Rodents; Soybean oil; Soybeans; Spectral analysis; Spectrophotometry; Studies; Urinalysis; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0899-9007; 1873-1244
• DOI: 10.1016/j.nut.2008.08.002

Abstract Objective This study reports the effects of feeding with a combination of inulin-type fructans (ITF) and fish oil (FO) on mineral absorption and bioavailability as part of a semipurified diet offered to rats. Methods Male Wistar rats ( n = 24) were fed a 15% lipid diet (soybean oil [SO] or a 1:0.3 fish:soybean oil mixture [FSO]) and diets containing the same sources of lipids supplemented with 10% ITF (Raftilose Synergy 1) ad libitum for 15 d. Feces and urine were collected for mineral analyses during the last 5 d of the test period. Fatty acid composition was determined in liver and cecal mucosa homogenates. Liver and bone mineral analyses were performed by atomic absorption spectrophotometry. Bone biomechanical analyses were evaluated by a 3-point bending test. Results Compared with the controls, ITF-fed rats had enlarged ceca and a significant decrease in cecal content pH ( P < 0.001). The apparent mineral absorption was improved in these rats, and this effect was enhanced by dietary combination with FO for all minerals except for magnesium. Addition of ITF to the diet resulted in higher bone mineral content (calcium and zinc) and bone strength, but increased bone mineral content was only statistically significant in FO-fed animals. A decrease in liver iron stores ( P = 0.015) was observed in rats fed FO, considering that ITF consumption returned to levels comparable to the SO control group. Conclusion These findings confirm the positive influence of ITF on mineral bioavailability, which was potentiated by addition of FO to the diet.