|Cote, Gregory - Greg|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2006
Publication Date: 12/1/2006
Citation: Sanz, M., Cote, G.L., Gibson, G., Rastall, R.A. 2006. Influence of glycosidic linkages and molecular weight on the fermentation of maltose-based oligosaccharides by gut bacteria. Journal of Agricultural and Food Chemistry. 54:9779-9784. Interpretive Summary: New value-added markets for agricultural commodities are highly desirable, and one potential area that could be exploited in this manner is nutritional supplements for food and feed. Complex carbohydrates were made from sugar and various other crop-derived carbohydrates using a food-grade bacterium. Different sized molecules were separated and each was analyzed for its ability to support the growth of beneficial or detrimental bacteria. Certain sizes were better than others at supporting the growth of good intestinal bacteria. The manner in which the sugar units were chemically bonded also influenced the ability to act as prebiotics. These results could help to find prebiotic oligosaccharides with more persistence in the colon. This research provides information that will be useful to scientists and to ingredient manufacturers in designing health-enhancing food and feed additives from agricultural commodities.
Technical Abstract: A structure-function study was carried out to increase knowledge of how glycosidic linkages and molecular weight of carbohydrates contribute towards the selectivity of fermentation by gut bacteria. Oligosaccharides with maltose as the common carbohydrate source were used. Potentially prebiotic alternansucrase (ASR) and dextransucrase (DSR) maltose acceptor products were synthesized and separated into different molecular weights using a Bio-Gel P2 column. These fractions were characterised by MALDI-ToF. Non-prebiotic maltooligosaccharides (MOS) of degree of polymerization (DP) from 3 to 7 were commercially obtained for comparison. Growth selectivity of fecal bacteria on these oligosaccharides was studied using an anaerobic in vitro fermentation method. In general, carbohydrates of DP3 showed the highest selectivity, however, oligosaccharides with higher molecular weight (DP6-DP7) also resulted in a selective fermentation. Oligosaccharides with DPs above 7 did not promote the growth of "beneficial" bacteria. These results could help to find prebiotic oligosaccharides with more persistence in the colon.