Coculture Fermentations ofBifidobacteriumSpecies andBacteroides thetaiotaomicronReveal a Mechanistic Insight into the Prebiotic Effect of Inulin-Type Fructans

Abstract

Four bifidobacteria, each representing a cluster of strains with specific inulin-type-fructan degradation capacities, were grown in coculture fermentations with Bacteroides thetaiotaomicron LMG 11262, a strain able to metabolize both oligofructose and inulin. In a medium for colon bacteria with inulin as the sole added energy source, the ability of the bifidobacteria to compete for this substrate reflected phenotypical variation. Bifidobacterium breve Yakult, a strain that was not able to degrade oligofructose or inulin, was outcompeted by B. thetaiotaomicron LMG 11262. Bifidobacterium adolescentis LMG 10734, a strain that could degrade oligofructose (displaying a preferential breakdown mechanism) but that did not grow on inulin, managed to become competitive when oligofructose and short fractions of inulin started to accumulate in the fermentation medium. Bifidobacterium angulatum LMG 11039T , a strain that was previously shown to degrade all oligofructose fractions simultaneously and to be able to partially break down inulin, was competitive from the beginning of the fermentation, consuming short fractions of inulin from the moment they appeared. Bifidobacterium longum LMG 11047, representing a cluster of bifidobacteria that shared both high fructose consumption and oligofructose degradation rates and were able to perform partial breakdown of inulin, was the dominating strain in a coculture with B. thetaiotaomicron LMG 11262. These observations indicate that distinct subgroups within the large-intestinal Bifidobacterium population will be stimulated by different groups of prebiotic inulin-type fructans, a variation that could be reflected in differences concerning their health-promoting effects.

Substrate-driven gene expression in Roseburia inulinivorans : Importance of inducible enzymes in the utilization of inulin and starch

“…This is in contrast to coculture studies with B. thetaiotaomicron and various Bifidobacterium strains (33). In these cases, B. thetaiotaomicron does release short-chain oligofructose molecules into the medium following extracellular inulin degradation, which different bifidobacterial species have varying abilities to use (33). Analysis of the activity of fractionated R. inulinivorans cells to degrade fructans did not indicate significant extracellular activity, although the cell pellets and sonicated material were active.…”

“…longum that uses fructose and scFOS was unable to grow in coculture with R. inulinivorans A2-194, indicating that there was no extracellular accumulation of monomeric units during degradation of inulin by R. inulinivorans. This is in contrast to coculture studies with B. thetaiotaomicron and various Bifidobacterium strains (33). In these cases, B. thetaiotaomicron does release short-chain oligofructose molecules into the medium following extracellular inulin degradation, which different bifidobacterial species have varying abilities to use (33).…”

Genomics of the Genus Bifidobacterium Reveals Species-Specific Adaptation to the Glycan-Rich Gut Environment

“…While B. breve is not known to be able to grow on mucin or HMOs, host-derived mono/oligosaccharides may become available through hydrolytic activities of other (bifido)bacteria present in the gut (e.g., B. bifidum and B. longum subsp. infantis), allowing B. breve strains to utilize such liberated carbohydrates through cross-feeding activities (74)(75)(76).…”

Bacteroides faecis sp. nov., isolated from human faeces

“…Some species of the genus Bacteroides, including Bacteroides thetaiotaomicron, are known to be decomposers in the colon by fermenting carbohydrates and catabolizing polysaccharides (hemicellulose and xylan) (Falony et al, 2009;Flint, 2006;Salyers, 1995;Van der Meulen et al, 2006). Novel strains of members of the genus Bacteroides from human faeces and intestinal organs have been identified using cultureindependent techniques based on 16S rRNA gene sequence analysis (Dore et al, 1998; Eckburg et al, 2005; Gill et al, 2006;Hayashi et al, 2003;Li et al, 2009;Palmer et al, 2007) and several novel species have recently been identified and characterized (Bakir et al, 2006a, b, c;Chassard et al, 2008; Hayashi et al, 2007;Kitahara et al, 2005;Robert et al, 2007;Song et al, 2004).…”