Structure of ?-glucan from Tibetan hull-less barley and its in vitro fermentation by human gut microbiota

Abstract Background The influence of ? -glucan on the human gut microbiota is closely related to physicochemical structure -glucan. We purified a homogeneous water-soluble polysaccharide from Tibetan hull-less barley 25 and studied its in vitro fermentation profile. Results Analysis by gas chromatography (GC), Fourier-transformed infrared (FT-IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), atomic force micrograph (AFM) helped determine be (molecular weight: 3.45 × 10 4 Da), which was further characterized as mixed-linkage (1 ? 3)(1 4)-linked - d -glucans. SEM images demonstrated an intricate web polysaccharide, while AFM revealed presence small spherical particles structure. In addition, composition group found altered, wherein abundance Pantoea , Megamonas Bifidobacterium Prevotella-9 were increased. On other hand, that significantly decreased pH value increased production acetate, propionate, butyrate. Conclusions Hull-less type dietary fiber, analysis suggested it may serve prebiotic food supplement for regulation microbiota.