In vitro fermentation of arabinoxylan from oat ( Avena sativa L.) by Pekin duck intestinal microbiota

Arabinoxylan (AX) is abundant in cereal grains used as feed for ducks. However, the duck intestinal microbes responsible for the degradation of AX are not fully understood. In this study, oat AX was degraded and utilized by different duck intestinal microbiota in vitro. Changes in short-chain fatty acids (SCFAs), branch-chain fatty acids, and the pH resulted from a 72-h AX fermentation in intestinal samples were measured. The addition of AX increased the concentration of isobutyric acid and decreased the concentrations of SCFAs. The pH values decreased significantly in the intestinal samples. Gut microbiota were assessed using high-throughput sequencing of the 16S ribosomal RNA gene, and the results indicated that AX stimulated the growth of Megamonas and Bifidobacterium species, with Megamonas exhibiting the greatest stimulation. Overall, the results suggest that oat AX is utilized by specific bacteria in duck intestines, providing the theoretical basis for the impacts of AX on animal health.