Nondigestible oligosaccharides increase calcium absorption and suppress bone resorption in ovariectomized rats

J Nutr. 2004 Feb;134(2):399-402. doi: 10.1093/jn/134.2.399.


Nondigestible oligosaccharides (NDO) including inulin and fructooligosaccharides (FOS) have been reported to stimulate calcium absorption. Here we report the effect of a mixture of inulin and FOS (Raftilose Synergy 1, Orafti) on calcium and bone metabolism in ovariectomized (OVX) rats. OVX rats (6 mo old) were fed a semipurified diet for 3 mo in our animal care laboratory for stabilization after ovariectomy. They were then divided into two groups (n = 13/group) and fed either a control or a NDO-supplemented diet (55 g/kg) for 21 d. Catheters were placed in their jugular veins. After 2 d, a tracer ((45)Ca) was administered by gavage or i.v. and blood was sampled for up to 300 min. Urine and fecal samples were collected for 4 d after (45)Ca administration. Femurs were measured for bone mineral density (BMD), breaking strength, and total calcium. Calcium absorption, femoral calcium content, BMD, and bone balance (V(bal)) were significantly increased (P < 0.05) by NDO, whereas the bone resorption rate relative to the bone formation rate was significantly depressed by NDO. We conclude that feeding NDO at 5.5 g/100 g for 21 d has a positive effect on calcium absorption and retention in ovariectomized rats.

MeSH terms

  • Absorption
  • Animals
  • Bone Resorption / metabolism*
  • Bone and Bones / metabolism*
  • Calcium / metabolism
  • Calcium / pharmacokinetics*
  • Digestion
  • Female
  • Oligosaccharides / administration & dosage
  • Oligosaccharides / pharmacology*
  • Ovariectomy
  • Rats
  • Rats, Sprague-Dawley


  • Oligosaccharides
  • Calcium