The study – published in the Journal of Food Science – reports that consumption of dietary fibres such as inulin and polydextrose could help to boost the uptake of minerals that are important for bone health.
Led by Professor Connie Weaver of Purdue University, USA, the researchers said the prebiotic fibres altered the way in which the rats absorbed calcium and magnesium from foods, meaning more of the minerals were absorbed.
“This work examines the impact of prebiotic supplementation on mineral metabolism and bone health using a postmenopausal rat model,” explained the research team.
Weaver and her colleagues said the study findings will help future investigations to ascertain factors related to the potential bone health benefits of prebiotics – which in turn could help in developing an effective prebiotics food product or supplement “that will address the bone health needs of consumers.”
Weaver and her colleagues noted that the steadily aging global population has led to higher incidences of several chronic diseases including osteoporosis, a bone disease that primarily affects postmenopausal women.
They explained that dietary fibre has been suggested to enhance calcium and magnesium absorption and utilisation, and could therefore have potential in reducing postmenopausal bone loss.
The concept is believed to work by promoting the growth of intestinal bacteria that can increase production of short chain fatty acids that modify the acidity of the gut, making minerals more soluble and easier to abrosb.
“Among prebiotics, oligosaccharides, fructoligosaccharides, and inulin are the most intensively studied for their ability to enhance mineral absorption and bone mineralisation,” they reported.
In the new study, Weaver and her team investigated whether dietary supplementation with dietary fibres alters the abrobtion and metabolism of calcium and magnesium.
The team fed postmenopausal rats mineral supplements, in addition to different dietary fibres – either an inulin-based fiber (Synergy1, BENEO, or Fruitafit HD, Sensus,) or a novel fiber (polydextrose, Tate & Lyle) – at 5% of diet four weeks of feeding.
They found that rats receiving polydextrose had significantly higher net calcium absorption efficiency and retention when compared to inulin-based fibers after early exposure but the advantage did not last over long-term exposure.
Inulin-based fibers had a long term positive effect on calcium metabolism that Weaver and her team explained were related to changes in the gut production of short chain fatty acids.
All fibres were found to improve magnesium absorption and retention.
Source: Journal of Food Science
Published online ahead f print, doi: 10.1111/j.1750-3841.2011.02612.x
“Prebiotics Enhance Magnesium Absorption and Inulin-based Fibers Exert Chronic Effects on Calcium Utilization in a Postmenopausal Rodent Model”
Authors: L.C.L. Legette, W.H. Lee, B.R. Martin, J.A. Story, J.K. Campbell, C.M. Weaver