Aims: The aim of this work was to analyse the growth of human faecal microbiota on barley dietary fibres (DF). It is generally accepted that insoluble DF are health promoting, but the information is scarce about how these fibres affect the gastrointestinal (GI) microbiota. A major reason for the limited knowledge is that there are currently no proper tools to analyse the complete GI microbiota.
Methods and results: Here we present a novel 16S rRNA gene analytical approach that enables the analyses of the complete microbiota, including the part that has not yet been characterized. The basic principle of the method is use of 16S rRNA gene signature sequences to determine both the phylogenetic relatedness and the distribution of bacteria in the samples analysed. Using this approach, we analysed the microbiota after in vitro fermentation of different barley fractions with human faeces. Our main finding was that groups of actinobacteria were selectively enriched by growth on the insoluble DF fractions.
Conclusions: Our novel analytical approaches revealed new enrichment patterns in the taxa that respond to insoluble DF.
Significance and impact of the study: Our results may have major implications for future understanding of insoluble DF health effects.