combination of prebiotic short- and long-chain inulin-type fructans enhances calcium absorption and bone mineralization in young adolescents

• Published in: The American journal of clinical nutrition Vol. 82; no. 2; pp. 471 - 476
• Main Authors: Abrams, Steven A, Griffin, Ian J, Hawthorne, Keli M, Liang, Lily, Gunn, Sheila K, Darlington, Gretchen, Ellis, Kenneth J
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01.08.2005; American Society for Clinical Nutrition, Inc
• Subjects: Absorption; Adolescent; adolescent nutrition; adolescents; Bioavailability; Biological and medical sciences; Bone Density; bone mineralization; Bones; Calcification, Physiologic; Calcium; Calcium - metabolism; Child; Diet; dietary fiber; Feeding. Feeding behavior; Female; Fructans - administration & dosage; Fundamental and applied biological sciences. Psychology; Genotype; Humans; intestinal absorption; inulin; Inulin - administration & dosage; Male; nutrient availability; nutrition-genotype interaction; Physical growth; prebiotics; puberty; stable isotopes; Vertebrates: anatomy and physiology, studies on body, several organs or systems; vitamin D-binding protein; Human; Puberty; stable isotopes; Short chain; Feeding behavior; Calcium; Growth; Long chain; Bioavailability; Prebiotics; Calcium absorption; Osteoarticular system; Daily; Absorption; Vitamin D; Food intake; Mineralization; Adolescent; Inulin; pubertal growth; vitamin D receptor; Bone; Isotopes; Biological receptor
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/82.2.471

BACKGROUND: Short-term studies in adolescents have generally shown an enhancement of calcium absorption by inulin-type fructans (prebiotics). Results have been inconsistent; however, and no studies have been conducted to determine whether this effect persists with long-term use. OBJECTIVE: The objective was to assess the effects on calcium absorption and bone mineral accretion after 8 wk and 1 y of supplementation with an inulin-type fructan. DESIGN: Pubertal adolescents were randomly assigned to receive 8 g/d of a mixed short and long degree of polymerization inulin-type fructan product (fructan group) or maltodextrin placebo (control group). Bone mineral content and bone mineral density were measured before randomization and after 1 y. Calcium absorption was measured with the use of stable isotopes at baseline and 8 wk and 1 y after supplementation. Polymorphisms of the Fok1 vitamin D receptor gene were determined. RESULTS: Calcium absorption was significantly greater in the fructan group than in the control group at 8 wk (difference: 8.5 ± 1.6%; P < 0.001) and at 1 y (difference: 5.9 ± 2.8%; P = 0.04). An interaction with Fok1 genotype was present such that subjects with an ff genotype had the least initial response to fructan. After 1 y, the fructan group had a greater increment in both whole-body bone mineral content (difference: 35 ± 16 g; P = 0.03) and whole-body bone mineral density (difference: 0.015 ± 0.004 g/cm²; P = 0.01) than did the control group. CONCLUSION: Daily consumption of a combination of prebiotic short- and long-chain inulin-type fructans significantly increases calcium absorption and enhances bone mineralization during pubertal growth. Effects of dietary factors on calcium absorption may be modulated by genetic factors, including specific vitamin D receptor gene polymorphisms.