Prebiotic fibers may enhance the absorption and retention in rats, suggests new data from Purdue University with implications for bone health in postmenopausal women.
Supplementation of the diet with commercial ingredients Synergy1 (Beneo), Fruitafit HD (Sensus) or polydextrose (Tate & Lyle) was associated with an increase in magnesium absorption and retention of about 20% and 23%, respectively, according to findings published in the Journal of Food Science.
Explaining the practical implications of their findings, the researchers note: “Steady growth in US middle-aged and elderly populations has led to higher incidences of several chronic diseases including osteoporosis, a bone disease that primarily affects postmenopausal women. Recent research suggests that certain dietary fibers (prebiotics) enhance mineral absorption and may impart bone health benefits.
“Study findings will aid future investigations in ascertaining the factors related to potential bone health benefits of prebiotic which will aid in developing an effective prebiotics food product/supplement that will address the bone health needs of consumers.”
This is not the first time that prebiotics have been reported to beneficially influence magnesium uptake. A study by Cargill and TNO Quality of Life from 2009 (Nutrition Research, Vol. 29, pp. 229-237) indicated that fructo-oligosaccharide consumption increased magnesium absorption in 12- to 15-year-old girls by 18% after 36 days.
The potential benefits of prebiotics include improved bone health, colon health, immunity, satiety, and weight management.
The chicory root is the major source of prebiotic ingredients. Inulin and oligofructose are the two major ingredients sourced from the root that is mainly grown in Belgium and Northern France where the world’s ‘big three’ suppliers (Beneo-Orafti, Sensus, Cosucra) are based.
The Purdue scientists divided female lab rats into six groups. The first group acted as the controls, while the other five groups had their ovaries removed to act as a model of post-menopausal conditions. One of the ovariectomized rat groups was fed the control diet only, one group received daily estradiol (E2) injections, and the other three groups had their daily diet supplemented with Synergy1, Fruitafit HD, or polydextrose at a level of 5%.
The researchers found that the polydextrose-fed rats had higher calcium absorption efficiency and retention than the other groups after a few days, but this difference was no longer observed after four weeks of feeding.
Both inulin-based fibers (Synergy1 and Fruitafit HD) produced positive effects on calcium metabolism related to changes in the gut, they said.
“Although prebiotics increased mineral absorption and utilization, the increase did not translate to improved indicators of bone strength suggesting that a four week dietary prebiotics treatment may not be sufficient to have a substantial impact on bone after stabilization following menopause,” they noted.
“Longer treatment duration as well as administration of treatment during growth or early or perimenopausal phase may produce larger benefits.”
Source: Journal of Food Science
Volume 77, Issue 4, Pages H88-94, 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.L. Legette, W. Lee, B.R. Martin, J.A. Story, J.K. Campbell, C.M. Weaver