|Sanz, Maria Luz - INSTIT DE QUIMICA|
|Rastall, Robert - UNIVERSITY OF READING|
|Gibson, Glenn - UNIVERSITY OF READING|
Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: September 14, 2006
Publication Date: September 14, 2006
Citation: Sanz, M., Rastall, R.A., Gibson, G.R., Cote, G.L. 2006. Influence of molecular weight in the fermentation of oligosaccharides by gut microflora [abstract]. American Chemical Society. Abstract No. AGFD 5. Technical Abstract: In recent times, many carbohydrates have been reported to exert a prebiotic effect, such as fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), and lactulose. Many others are still under investigation for their prebiotic potential. There is, however, a lack of basic understanding of the mechanisms by which carbohydrates operate and the influence of their structures on gut microflora. In this work the effect of molecular weight of different oligosaccharides (maltooligosaccharides, gentiooligosaccharides, alternansucrase-derived maltose and gentiobiose acceptor oligosaccharides, and dextransucrase-derived maltose acceptor oligosaccharides) on gut microflora was studied. The last three products were prepared by using alternansucrase and dextransucrase isolated from Leuconostoc mesenteroides NRRL B-21297 and NRRL B-512F, respectively. Oligosaccharides were fractionated in their molecular weights using Bio-Gel P2 columns. Fractions were characterized using MALDI TOFS and TLC and submitted to in vitro fermentation with fecal samples. Quantitative bacterial population changes were characterized using fluorescence in situ hybridization (FISH) analysis. The highest selectivity for probiotic bacteria was achieved for DP3, DP4, and DP5 oligosaccharides with gentiobiose-derived oligosaccharides. However, with maltose-derived oligosaccharides the greatest prebiotic index values were exhibited by DP3 and DP6. Oligosaccharides of DP higher than 7 did not present any positive prebiotic effect on gut microflora in vitro. The structure-function information obtained in this study may lead to a predictive understanding of how specific carbohydrate structures are fermented by the human gut microflora. These results can help in the development of novel carbohydrates with prebiotic properties.