Short-term consumption of novel medium-chain arabinoxylan product selectively enriches gastrointestinal bifidobacteria and alters microbiome population structure in healthy-obese human volunteers

Background/Objectives: Arabinoxylan oligosaccharides (AXOS) are a promising class of potential probiotics with proven bifidogenic and butyrogenic effects in humans, however the specific prebiotic properties and health effects are dependent upon its structure, particularly the average degree of polymerisation (avDP). The effect of an AXOS with a medium avDP upon the gut microbiota has not been tested in humans; therefore we sought to determine the impact of a novel medium avDP AXOS upon the human faecal microbiota using 16S rRNA gene high-throughout sequencing. Results/Conclusions: A 23-day cross-over dietary intervention trial was conducted using 20 healthy-obese volunteers consuming an AXOS-enriched diet. Illumina sequencing of the 16S rRNA V4 region revealed that consumption of a medium avDP AXOS significantly altered the composition and structure of the human faecal microbiome. A major expansion of the faecal Bifidobacterium population was observed in the majority of volunteers following the AXOS diet, resulting in this one prebiotic genus accounting for an average 1/5th of the total microbial population. This substantial bifidogenic enrichment was mainly driven by a single Bifidobacterium species; Bifidobacterium adolescentis. We demonstrate that dietary supplementation with a medium avDP AXOS significantly alters the faecal microbiome by enriching for probiotic species.