Fine-tuning dietary fibre to target gut microbiota accessibility

The project will explore the bioaccessibility of prebiotic fibres from natural matrices and their accessibility to the human gut microbiota. Most of the evidence on the efficacy of prebiotics (fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), arabinoxylan-oligosaccharides (AXOS)) has been collated using the extracted and highly refined oligomers. There is an increasing emphasis on minimally processed foods and moves away from highly refined materials would meet this need. Such minimal processing of natural plant-based starting materials which control the accessibility of the constituent oligomers might include fermentation, the use of enzymes, technologies such as pulse electric fields and thermo/physico mechanical pre-processing and the degree of ripening of the starting material. These processes will create changes in both the degree of polymerization of the 'parent' polysaccharide and the diffusivity of the oligosaccharides from the natural matrices - which fine-tunes accessibility of the fibre by the gut microbiota. This project will use models of the human gut microbiota combined with cutting-edge metabolomics and metagenomics to study the impact of processing of fibre on gut microbiota composition and microbial accessibility.
The project therefore sits at the interface between physical sciences and microbiome science and will an innovative comparison of fibre sources and the extent to which they can be controlled through pre-processing, to measure the effect on in gut fermentation, and subsequent effects on the gut microbiota and metabolic markers.