High molecular weight barley β‐glucan supports bacterial populations beneficial for gut health (647.45)

Abstract

Effects of short‐term consumption of barley β‐glucan (BBG) on gut microbiota were investigated using a controlled, single‐blinded, randomized crossover study consisting of four phases of 35 d intervention, each separated by 28d washout intervals. Subjects (n=22) received wheat and rice based control diet (CD), barley diet (BD) with 5g/d low molecular weight (MW) BBG, BD with 3g/d high MW BBG, or BD with 3g low MW BBG. DNA was extracted from feces taken at the end of each phase and the V4 region of bacterial 16S rRNA genes amplified and subjected to illumina sequencing. Data were analyzed using MIXED and GLIMMIX procedures of SAS, PLS‐DA of SIMCA and PERMANOVA of PRIMER. β‐Diversity of microbiota was affected by treatments (P = 0.02) with the most significant difference observed between 3g/d high MW compared to CD. At the phylum level, 3g/d high MW decreased (P < 0.001) Firmicutes (77.7% vs. 88.8%) and increased Bacteroidetes (18.2% vs. 10.0%) compared to CD. Among the core genera, 3 g high MW increased Bactroides (11.3% vs. 6.7%; P = 0.01) compared to CD. Other taxa which were positively associated with 3g high MW BBG included Prevotella, Akkermansia, Rikenellaceae and Lachnospiraceae. Data suggest that consumption of 3g/d high MW BBG supports particular bacterial populations that are beneficial to gut health.