The Effect of a Long Term Synbiotic Diet on Cortical Bone Growth in Aging Mice

Studies have shown that cortical bone atrophy occurs in aging animals. A treatment for prevention of cortical bone atrophy could include a synbiotic diet, yet there is little research in this area. We hypothesize that dietary supplementation of prebiotics and probiotics (i.e. a synbiotic diet) will aid in the prevention of cortical bone atrophy in aging mice. Probiotics are beneficial intestinal microorganisms while prebiotics are foods for the microorganisms. To test this hypothesis, cortical wall thickness wwas measured in the proximal region of the femur bone as an index of bone strength and growth. Thirty albino male mice, ten months of age, were randomly assigned into three groups: baseline, sacrificed at time zero; control, fed control diet for 4 months; and synbiotic, fed synbiotic diet for 4 months. The control and synbiotic groups were sacrificed at 14 months of age. Then, the femur bones were dissected, dehydrated in 70% ethanol, and embedded in methylmethacrylate. The bones were sliced in cross-section to a thickness of 5 µm, using a saw microtome with a diamond blade. The slices were analyzed using a Leica DM 1000 LED and Q-Capture Pro7. Baseline and control groups had no significant difference in cortical wall thickness, whereas the synbiotic group was significantly thinner compared to both groups. The results are preliminary, but do not appear to support the hypothesis that a synbiotic diet enhances cortical wall thickness in aging mice.