The study, published in the European Journal of Clinical Nutrition, suggests that supplementation with the dietary plant-derived polysaccharides may result in significant changes in serum protein glycosylation – an important enzymatic process in cells that is linked to changes in immune response.
“Our study reports novel findings showing that the ingestion of a standardized mixture of plant-derived polysaccharides can induce significant changes in the N-glycosylation status of serum glycoproteins in normal healthy individuals,” said the researchers, led by Azita Alavi from St George's University of London, UK.
“Given that glycosylation is a key post-translational modification that can significantly affect the overall biophysical and biochemical functions of proteins, the observed shift in the glycosylation status of serum glycoproteins in response to supplementation may be significant,” they added.
The study was in part funded by Texas-based Mannatech Inc – who also provided the Advanced Ambrotose mixed saccharide dietary supplement. However the authors stated that Mannatech had no role in the study execution or reporting of its results.
Plant fiber
Fueled by the current interest in linking diet and health, the authors noted the recent surge of research by various groups into the biological activities and potential beneficial effects of dietary plant fibers.
These signify a range of structurally diverse, non- or low-digestible, dietary soluble fibers derived from plants, including fungi, lichens and algae. Such fibers have been demonstrated to beneficially affect one or more target cellular or body functions, added the authors.
“In-vitro and in-vivo studies suggest that certain dietary saccharide biopolymers can have bifidogenic and or immuno-modulatory effects, and that some could represent preferential substrates or precursors that can impact cellular glycosylation,” they said.
The authors therefore aimed to investigate the possible affects, if any, of plant polysaccharides on the glycosylation status of serum glycoproteins.
“We chose a commercial, mixed saccharide dietary supplement … the constituents of which have previously been shown to exhibit prebiotic, as well as possible immunomodulatory activities,” they said.
The mixed saccharide supplement used in the study was Advanced Ambrotose (AA) powder, provided by Mannatech.
Study details
The twelve trial participants were monitored for changes in plasma glycan profiles for a period of seven weeks pre-supplementation. Following this period, the volunteers were supplemented with increasing doses of AA supplement – weeks 1to 4 at 1.3 grams per day; weeks 5 to 6 at 2.6 grams per day and week 7 to 8 at 5.2 grams per day.
“Comparison of the glycan profiles during the supplementation period with the time trends observed during the pre-supplementation period detected distinct changes in the relative intensities of seven of eight glycans studied. These changes were particularly striking within the first 1–2 weeks of supplementation,” said Alavi and colleagues.
They noted that further analysis revealed a dose-dependent response.
“We have demonstrated that supplementation with dietary plant polysaccharides in AA can result in significant serum protein glycomodifications in normal healthy individuals,” said the researchers.
“These finding are interesting and merit further research, where it is hoped that an integrative approach … focusing on the gut associated microbe–host mutualism and its impact on physiology, can help unravel the exogenous and endogenous effects of dietary components and hence, generate novel hypotheses for innovative dietary interventions that may impact health,” they concluded.
Source: European Journal of Clinical Nutrition
Published online ahead of print, doi: 10.1038/ejcn.2010.263
“An open-label dosing study to evaluate the safety and effects of a dietary plant-derived polysaccharide supplement on the N-glycosylation status of serum glycoproteins in healthy subjects”
Authors: A. Alavi, O. Fraser, E. Tarelli, M. Bland, J. Axford