Improving effect of feeding with a phosphorylated guar gum hydrolysate on calcium absorption impaired by ovariectomy in rats

We have previously reported that a phosphorylated guar gum hydrolysate (P-GGH) promoted calcium absorption and the accumulation of bone calcium in rats. We now investigate the effect of P-GGH (50 g/kg of diet) on the intestinal calcium absorption and bones of ovariectomized (OVX) rats in comparison with sham-operated rats over a six-week ingestion period. The apparent calcium absorption was decreased by aging and ovariectomy in the rats fed on the control and GGH diets (50 g/kg of diet), but not in the rats fed on the P-GGH diet. The absorption was higher in the P-GGH group than in the GGH and control diet groups in the fourth and sixth weeks after feeding the test diets to OVX rats. Femoral calcium and strength were decreased by OVX in the rats fed on the control and GGH diets, but not in the rats fed on the P-GGH diet. The values of these parameters were higher in the P-GGH group than in either the control or GGH group of OVX rats. The amount of soluble calcium in the ileal contents was higher in the P-GGH group than in the control and GGH groups. These results indicate that P-GGH may be useful for preventing the reduction of intestinal calcium absorption and bone in the condition of estrogen deficiency.