Fermentation of feruloyl and non-feruloyl xylooligosaccharides by mixed fecal cultures of human and cow: a comparative study in vitro

For the first time, a comparative study was undertaken with respect to the fermentation of (a) monosaccharides (glucose, galactose, arabinose, and xylose); (b) disaccharide (lactulose); (c) Jerusalem artichoke; (d) xylooligosaccharides (XO); and (e) feruloyl xylooligosaccharides (FXO) by mixed fecal cultures of human and cow. Among monosaccharides, arabinose and xylose exhibited prebiotic properties, and among these arabinose was found to be a better substrate than xylose. Glucose and galactose did not have any impact with respect to either increase or decrease in different bacterial populations present in both human and cow feces and liberated very small amounts of SCFA indicating them to be the least prebiotic among all the substrates tried. Both lactulose and Jerusalem artichoke increased the lactobacilli and bifidobacteria in pooled fecal cultures of human and cow. Bovine fecal bacteria utilized XO and FXO more effectively than human fecal bacteria as indicated by relatively high levels of the cell wall–degrading enzyme activities. Growth of different bacterial populations was monitored by the fluorescent in situ hybridization method at 12 and 24 h. XO increased the growth of lactobacilli and bifidobacteria and decreased the growth of Bacteriodes and clostridia, whereas FXO increased the growth of lactobacilli in cow fecal cultures. In human fecal cultures, FXO promoted the growth of bifidobacteria, but to a lesser extent compared with cow fecal bacteria. Quantitative variations were observed with respect to the profile of short-chain fatty acids liberated in the fecal culture filtrates of human and cow grown on XO and FXO.