EFFECTS OF THE FRUCTOOLIGOSACCHARIDES (FOS) AND INULIN ON BONE METABOLISM OF THE SKELETALLY MATURE FEMALE RATS Efeitos dos frutooligossacarídeos (FOS) e inulina no metabolismo ósseo de ratas esqueleticamente maduras.

The aim of this study was establish if the fructooligosaccharides (FOS) and inulin alone or together attenuate age related bone loss in skeletally mature female rats. Forty 10-month old female rats were randomly assigned to four diet groups for 2 months: control, FOS, inulin and FOS + inulin. Bone mineral density (BMD) using dualenergy X-ray absorptiometry (DXA); femur quality using morphometry and biomechanic properties; biochemical assays by the determination of serum parathyroid hormone (PTH), alkaline phosphatase activity (ALP), degradation products of C-terminal peptides of type I collagen (CTX-I), osteocalcin (OC), osteoprotegerin (OPG) and nuclear factor κappa B ligand (RANk-L). The FOS increased hip axis BMD (0.255 ± 0.005 g/cm2) and femur neck width (2.19 ± 0.01 mm) and reduced PTH (4.0 x 10-3 ± 0.0006 μg/L); FOS + inulin increased the femur proportional limit (87.2 ± 1.0 N) and reduced PTH (2.5 x 10-3 ± 0.0006 μg/L) and ALP (23.2 ± 5.1 U/L); all the prebiotics reduced OPG (FOS = 1.1 ± 0.3; inulin = 1.1 ± 0.3; FOS + inulin = 1.4 ± 0.4 μg/L) and RANk-L (FOS = 1.65 x 10-2 ± 0.003; inulin = 1.78 x 10-2 ± 0.003; FOS + inulin = 2.83 x 10-2 ± 0.006 μg/L ); no prebiotics changed OC and CTX-I. The results suggested that the consumption of FOS or FOS + inulin may reduce the bone turnover, however, further studies about prebiotics and their synergistic effect on age related bone loss are required.