In vitro fermentation of cereal dietary fibre carbohydrates by probiotic and intestinal bacteria

Abstract

A range of probiotic and other intestinal bacteria were examined for their ability to ferment the dietary ®bre carbohydrates b-glucan, xylan, xylo-oligosaccharides (XOS) and arabinoxylan. bGlucan was fermented by Bacteroides spp and Clostridium beijerinckii but was not fermented by lactobacilli, bi®dobacteria, enterococci or Escherichia coli. Unsubstituted xylan was not fermented by any of the probiotic bacteria examined. However, many Bi®dobacterium species and Lactobacillus brevis were able to grow to high yields using XOS. XOS were also ef®ciently fermented by some Bacteroides isolates but not by E coli, enterococci, Clostridium dif®cile, Clostridium perfringens or by the majority of intestinal Lactobacillus species examined. Bi®dobacterium longum strains were able to grow well using arabinoxylan as the sole carbon source. These organisms hydrolysed and fermented the arabinosyl residues from arabinoxylan but did not substantially utilise the xylan backbone of the polysaccharide. Arabinoxylan was not fermented by lactobacilli, enterococci, E coli, C perfringens or C dif®cile and has potential to be an applicable carbohydrate to complement probiotic Bif longum strains in synbiotic combinations.

The source of fermentable carbohydrates influences the in vitro protein synthesis by colonic bacteria isolated from pigs

“…However, xylans and pectins are first metabolised by the pentose-phosphate pathway (Macfarlane and starting from the pentose to fructose-6-phosphate and glyceraldehyde-3-phosphate via xylulose-5-phosphate (Prescott et al, 1996). This reduces the bacterial growth rates as reported by Crittenden et al (2002) who compared xylose and xylo-oligosaccharides with glucose. It explains, beyond the rate of hydrolysis, the lowest BNI values observed for xylan (515 g xylose per kg DM) and pectin (672 g glucuronic acid per kg DM) in experiment 1 and wheat bran (251 g xylose per kg DM) in experiment 2.…”

Microbial Load and Keeping Quality of Kunu under Various Preservative Regimes

“…Also probiotic-rich fermented products can slow down aging process, ease digestive distress, and boost energy and immunity. Cereal based products are reported to harbour probiotic bacterial communities including Bifidobacterium spp, Lactobacillus brevis, Weissella confusa, Streptococcus lutetiensis, Streptococcus gallolyticus [9,10], since these cereals and their components may be exploited as a fermentation substrate capable of imparting even pre-biotic effects [11]. Although Neurospora sitophila was found in the edible preparation, this fungus, usually encountered in its anamorphic form, is generally regarded as 'safe' because it has not been implicated in mycotoxin production.…”

Carbohydrate metabolism in Bifidobacteria

“…Also different B. longum subsp. longum strains, including B667, were shown to produce arabinofuranohydrolases during growth on arabinoxylan [12,69], although these enzymes do not appear to be a typical feature in bifidobacterial genomes. Nevertheless, arabinan, arabinogalactan and arabinoxylan are considered potential prebiotics that support growth of certain bifidobacterial strains [147].…”