Same nondigestible oligosaccharides (NDOs) stimulate Ca and phosphorus (P) absorption and improve bone mass. The effect of NDOs appears to be more important when the diet does not meet Ca nutritional recommendations. Oestrogen deficiency induces a loss of bone mass which is greater if the intake of Ca is insufficient. The objective was to evaluate the effect a mixture of galactooligosaccharides (GOS) and fructooligosaccharides (FOS) (GOS/FOS®) (9:1) added to a low or a normal Ca diet on Ca and P absorption, bone retention, mineralisation and structure in osteopenic-oestrogen deficient rats. Female adult Wistar rats were OVX and remained untreated for 45 days to become osteopenic. Then, they were randomly assigned to receive for an additional 45-day period (T90) one of the following treatment: C5: AIN93-M containing 0.5% Ca; P5: C5+2.5% GOS/FOS®, C3: AIN93-M containing 0.3% Ca; P3: C3+2.5% GOS/FOS®. Body weight (BW) and intestinal lactobacilli count (UFC) were evaluated weekly. Ca and P absorptions were assessed at baseline and T90. Caecum pH, femoral Ca and P content, total skeleton BMC and BMD (Lunar DXA), bone volume (BV/TV), bone-breaking strength, elastic modulus and stiffness were determined at T90. Results: No differences in BW were observed. Caecum pH decreased while UFC (p<0.0001); Ca and P absorption (p<0.05); femur Ca and P content (p<0.01); BMC (p<0.05); BV/TV; bone-breaking strength; elastic modulus and stiffness (p<0.05) increased in P5 and P3 vs. C5 and C3, respectively. In conclusion, the used GOS/FOS® mixture increased Ca bioavailability that improved bone health during oestrogen withdrawal.
Disclosure: Grant of PIP004 and ® N.V.Nutricia.