Writing in Nature’s Scientific Reports, Italian and Irish researchers point to the ability of 100 bifidobacterial strains to use this substrate as its sole carbon source.
Further analysis points to Bifidobacterium breve as the most effective bacterial species in using CG for growth reflect the ability of this typical infant gut colonizer to use host-produced glycans, whose molecular structure partially resembles that of CG.
“These findings reinforce the potential of GC in modulating and shaping the bifidobacterial communities especially in ecological conditions where bifidobacteria are depleted (e.g., very often associated with metabolic disorders or gut diseases,” the team said.
”In this context, the capability of bifidobacteria to use the CG as carbon source and the subsequent degradation of this bio-polymer in simpler derivatives, i.e. chitooligosaccharides (COS), may support the notion that CG act as a prebiotic.
CG a Novel Food
CG is considered a viable food supplement, with the European Commission designating the compound as a novel food ingredient in 2011 and assigning a maximum consumption rate of 5 grams (g) per day for the average person.
However, humans are unable to degrade CG, giving rise to the notion that it could exert prebiotic effects in the large intestine influencing growth and/or metabolic activity of the gut microbiota.
Bifidobacteria are very prevalent and abundant human gut microbiota members, especially during the first months following birth, though their numbers decrease following weaning and in elderly.
The bacteria’s abundance in the human microbiota is markedly reduced following gastrointestinal diseases, suggesting a positive role in the promotion of host health.
However, there is limited scientific evidence available linking a prebiotic effect of CG towards members of the Bifidobacterium genus.
Using KitoZyme’s patented chitin and beta-glucan co-polymer, the research team, based at the University of Parma, looked at the ability of CG to influence growth of 100 bifidobacterial strains residing in the infant and adult human gut.
Such analyses were coupled with transcriptome experiments directed to explore the transcriptional effects of CG on Bifidobacterium breve 2L, which was shown to elicit the highest growth performance on this natural polysaccharide.
In addition, an in vivo trial involving a rat model revealed how the colonisation efficiency of this bifidobacterial strain was enhanced when the animals were fed with a diet containing CG.
Results indicated that CG proved a valuable novel prebiotic compound that may be added to the human diet in order to re-establish/reinforce bifidobacteria colonization in the mammalian gut.
“Such in vivo data should be further confirmed by clinical trials performed in human beings consuming CG or CG-based products (e.g., symbiotic products) in those categories of individuals where bifidobacterial abundance is naturally low,” the study team recommended.
“For example in the elderly or is depleted as a consequence of metabolic disorder (e.g., constipation) or diseases (auto-immune diseases) as well as antibiotic therapy.”
The study also argued that cross-feeding interactions might be established by the different members of the bifidobacterial communities as well as with the different members of the human gut microbiota for the complete metabolism of CG.
“This was previously shown in co-participated trophic interactions where a partner partially metabolises GC in favour to another microorganism that is genetically incapable to utilise this substrate,” the study added.
“Thus, cross-feeding might represent another valuable way exploited by CG to induce a more general prebiotic effect in the human gut.”
Source: Scientific Reports
Published online: doi.org/10.1038/s41598-019-42257-z
“Ability of bifidobacteria to metabolize chitin-glucan and its impact on the gut microbiota.”
Authors: Giulia Alessandri et al.