Fortifying ready-to-eat breakfast cereal with prebiotic wheat bran extracts can selectively enhance the growth of beneficial bacteria, say results from a double-blind, randomized, controlled, crossover trial.
Three weeks of consumption of an arabinoxylan-oligosaccharide-enriched cereal were associated with significant increases in bifidobacteria levels in the feces, according to findings published in Nutrition .
“Shifts in intestinal bacteria populations occurring with prebiotic consumption typically involve increased levels of bifidobacteria, which have been shown in animal and human studies to inhibit the growth of pathogenic bacteria, modulate the immune system, produce digestive enzymes, and help restore the gut microbiota after antibiotic use and lactobacilli, which control the proliferation of gut microbiota by producing antimicrobial compounds,” wrote the researchers, led by Kevin Maki, PhD, from Biofortis-Provident Clinical Research.
The other researchers were affiliated with the University of Reading (UK), the Kellogg Company (USA), the University of Toronto (Canada), the Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University (USA), and the University of Saskatchewan (Canada).
Dr Maki told NutraIngredients-USA that the researchers we were pleased with the results from the study.
"The AXOS ingredient is made by Fugeia in Belgium. They have undertaken several studies, of which ours was only one. For our trial they partnered with Kellogg to test AXOS in a breakfast cereal," he added.
The study adds to a previous study using arabinoxylan-oligosaccharides in bread . For that study, researchers from the University of Reading, UK and Puratos reported that 21 days of consuming arabinoxylan-oligosaccharides-enriched breads boosted bifidobacteria levels in feces and increased fermentation end products such as the short chain fatty acid butyrate (Nutrition Journal, 2012, 11:36).
Prebiotics are defined as: "Non-digestible substances that provide a beneficial physiological effect on the host by selectively stimulating the favorable growth or activity of a limited number of indigenous bacteria".
For the new study, Dr Maki and his co-workers recruited 55 healthy men and women aged between 18 and 75 to participate in their study. Participants were randomly assigned to receive 0, 2.2, or 4.8 grams per day of arabinoxylan-oligosaccharides (AXOS) as part of ready-to-eat cereal.
After three weeks of consumption the participants had two weeks without prebiotic consumption as a washout period before crossing to a different group. The volunteers participated in all three intervention groups.
Results showed that the highest dose of AXOS was associated with the highest increase in bifidobacteria levels, compared to the lower AXOS dose and the control cereal.
On the other hand, no significant changes were observed in other gut microbe species, they said.
The researchers did record a dose-response increase in ferulic acid levels after the meals, meaning that the greater the AXOS dose, the greater the increase.
The relatively small increase in ferulic acid did not lead to a significant increase in blood antioxidant measurements, however, and this was probably due to the lower levels of the acid compared with other circulating antioxidants such as vitamins C and E.
“The results of this study demonstrated the prebiotic activity of AXOS when used as an ingredient in a ready-to-eat wheat-based cereal and are in agreement with the findings of previous studies in which AXOS was consumed,” concluded the researchers.
Published online ahead of print, doi: 10.1016/j.nut.2012.02.010
“Digestive and physiologic effects of a wheat bran extract, arabino-xylan-oligosaccharide, in breakfast cereal”
Authors: K.C. Maki, G.R. Gibson, R.S. Dickmann, C.W.C. Kendall, C.-Y.O. Chen, A. Costabile, E.M. Comelli, D.L. McKay, N.G. Almeida, D. Jenkins, G.A. Zello, J.B. Blumberg