Arabinoxylan (AX) is a structural polysaccharide found in wheat, rice and other cereal grains. Diets high in AX-containing fiber may promote gut health in obesity through prebiotic function. Thus, the impact of soluble AX isolated from rice bran fiber on human gut microbiota phylogenetic composition and short-chain fatty acid (SCFA) production patterns from normal-weight and overweight/obese subjects was investigated through in vitro fecal fermentation. Results showed that rice bran arabinoxylan modified the microbiota in fecal samples from both weight classes compared to control, significantly increasing Collinsella, Blautia and Bifidobacterium, and decreasing Sutterella, Bilophila and Parabacteroides. Rice bran AX also significantly increased total and individual SCFA contents (p < 0.05). This study suggests that rice bran AX may beneficially impact gut health in obesity through prebiotic activities.
Keywords: arabinoxylan; gut microbiome; rice bran fiber; short-chain fatty acids.