title: Inulin effects on bioavailability of soy isoflavones and their calcium absorption enhancing ability.
abstract: The effect of inulin on isoflavone absorption and the effect of isoflavones and synergy with inulin on calcium absorption in rats was investigated. Rats (n = 48) were divided into three groups and fed inulin (50 mg/g), isoflavone (8 mg/g) or inulin + isoflavone (50 mg/g + 8 mg/g) diets for 21 days. After a 2-h fast, rats were given (45)Ca orally or intraperitoneally, together with 25 mg of calcium as calcium acetate. Blood and femurs were collected 4 days later. Sera were analyzed for isoflavones using HPLC-MS, femurs for (45)Ca by beta-scintillation counting, and total femoral calcium by atomic absorption spectroscopy. Both groups fed isoflavones had similar and significantly higher weight-adjusted total femoral calcium content compared to the inulin-fed group (p < 0.0001). (45)Ca absorption was significantly higher (p < 0.01) when isoflavones were added to the diet, and serum equol was significantly lower (p < 0.01) when inulin was added to the diet containing isoflavones. We conclude that isoflavones enhance calcium absorption, without synergy from inulin, and that inulin decreases equol production.
authors.affiliation: Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Tasleem A
authors.initials: TA
authors.lastname: Zafar
authors.forename: Connie M
authors.initials: CM
authors.lastname: Weaver
authors.forename: Kenneth
authors.initials: K
authors.lastname: Jones
authors.forename: D Ray
authors.initials: DR
authors.lastname: Moore
authors.forename: Stephen
authors.initials: S
authors.lastname: Barnes
mesh_terms: D000042:Absorption; D000818:Animals; D001682:Biological Availability; D002118:Calcium / Q000493:pharmacokinetics*; D004032:Diet; D005269:Femur / Q000378:metabolism; D007444:Inulin / Q000494:pharmacology*; D007529:Isoflavones / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013025:Glycine max / Q000737:chemistry*
chemical_list: D007529:Isoflavones; D007444:Inulin; D002118:Calcium