Role of arabinoxylan in the human gut microbiota

The gut microbiota plays a crucial role in the conversion of dietary fibre, affecting the health-promoting effects in the host. Dietary fibre may exert beneficial effects through modulation of the intestinal microbiota and metabolic end products. Arabinoxylan is a hetero-polysaccharide consisting of a linear xylose backbone with variable arabinose substitution. It is the main dietary fibre component in wheat and rye. The selectivity of dietary arabinoxylan in stimulating restricted set of microorganisms has, however, not been systematically evaluated. In this study, we investigated the effect of arabinoxylan, performing in vitro anaerobic incubations of human faecal microbiota amended with arabinoxylan and in the presence of the cellular activity marker (L-azidohomoalanine [AHA]) to detect arabinoxylan-stimulated cells. With this approach we were able to identify which microorganisms are stimulated by the presence of arabinoxylan.