Novel fibers increase bone calcium content and strength beyond efficiency of large intestine fermentation.

Dietary fibers are thought to benefit bone health through increasing mineral absorption and retention following fermentation in the lower gut and solubilization of minerals. This study compared eight fibers to cellulose following a 12 week intervention for production of short-chain fatty acids (SCFA), calcium absorption, mineral retention and bone content, and bone density and strength in a weanling rat model. Benefits to bone were poorly to modestly related to SCFA production, calcium absorption, or mineral retention, but some parameters were better predicted by cecal content weight, suggesting other mechanisms may be important. Nevertheless, two resistant starches, a soluble fiber dextrin and Polydextrose, increased bone calcium content. Soluble corn fiber and soluble fiber dextrin had the greatest benefit to bone properties including whole body bone mineral content and density and greater volumetric bone mineral density, cortical thickness and area, and peak breaking strength of the distal femur.