Influence of disaccharide structure on prebiotic selectivity in vitro.
To obtain structure-function information of a range of carbohydrates, which are available only in very small quantities, an in vitro fermentation method using 7 mg of carbohydrate, 0.7 mL of basal medium, and 1% (w/v) of fecal bacteria was validated against a pH-controlled batch culture with 150 mL of basal medium and 1.5 g of test carbohydrate. This method was used to determine the influence of different glycosidic linkages and monosaccharide compositions of disaccharides on the selectivity of microbial fermentation. A prebiotic index (PI) was calculated for each disaccharide. Generally, disaccharides with linkages of 1-2, 1-4, and 1-6 generated a high PI score, with kojibiose and sophorose showing the greatest values (21.62 and 18.63, respectively). Apart from 6alpha-mannobiose, mannose-containing disaccharides gave a low PI due to low numbers of bifidobacteria and lactobacilli and an increase in bacteroides. The structure-function information obtained in this study may lead to a predictive understanding of how specific structures are fermented by the human gut microflora.
Sanz
María Luz
ML
School of Food Biosciences, The University of Reading, Whiteknights, Berkshire, UK.
Gibson
Glenn R
GR
Rastall
Robert A
RA
D001419:Bacteria / Q000378:metabolism; D002236:Carbohydrate Conformation; D004187:Disaccharides / Q000737:chemistry* / Q000378:metabolism*; D005285:Fermentation; D008358:Mannose / Q000032:analysis; D019936:Probiotics / Q000737:chemistry* / Q000378:metabolism*; D013329:Structure-Activity Relationship
D004187:Disaccharides; D008358:Mannose