Calcium Absorption, Retention And Bone Calcium Content Are Enhanced By Different Fibers In Male Sprague Dawley Rats

Resistant starches and other fibers may be good candidates as enhancers of calcium absorption. This study investigated the effect of 8 fibers on calcium absorption and retention in rats fed a nutritionally adequate diet. Four week old male Sprague Dawley rats were assigned to a diet containing cellulose (control) or 1 of 8 different fibers: PROMITOR(tm) resistant starch 60 (RS60), resistant starch 75(RS75), soluble fiber dextrin(SFD), pullulan, PROMITOR(tm) soluble corn fiber(SCF), Sta‐Lite® poly‐dextrose(PDX), inulin, or inulin/FOS blend. At the end of a 12 week feeding period rats received DXA scans to measure bone density. Mineral balance was measured in metabolic cages for 3 days. At the end of the experiment rats received a test meal containing approximately one‐fourth of their daily intake labeled with 45 Ca Cl 2 . Calcium absorption was measured by femur uptake. Femurs, tibias, cecal and colon contents were harvested at the time of sacrifice. Bone mineral composition, density and cecal short chain fatty acid contents were analyzed. Femur calcium uptake was enhanced by inulin/FOS. Femur calcium concentration was significantly higher with RS60, RS75, inulin, SFD and PDX. All fibers tested formed greater quantities of cecal short chain fatty acids. However, those significantly different from control included SFD, pullulan, SCF, PDX, inulin and inulin/FOS. Sponsored by Tate and Lyle Health and Nutrition Sciences.