Structural Characterization and Regulatory Effect on Gut Microbiota of Selenium‐Enriched Polysaccharide of Auricularia auricula

ABSTRACT Auricularia auricula (AA) demonstrates potential as a natural source for human selenium supplementation. This study centered on the preparation of selenium‐enriched polysaccharides of AA (SAA) from selenium‐enriched AA, along with an analysis into their structural characteristics and influence on gut microbiota. The findings indicated that SAA exhibits an inorganic selenium conversion efficiency of 88.90%, is composed of six monosaccharides, and exhibits a molecular weight of 3621.63 kDa. Characteristic absorption peaks corresponding to Se═O and Se–O bonds were indicated in the FT‐IR analysis of SAA, and its surface displayed an organized network structure. The SAA group showed 5.54 nmol/g lower malondialdehyde (MDA) content and 12.93% higher superoxide dismutase (SOD) activity than the polysaccharides of AA group. Moreover, SAA promoted the growth of particular gut microbiota, notably the phylum Bacteroidetes, the family Bifidobacteriaceae, and the genus Bifidobacterium . In conclusion, SAA not only boosts the antioxidant capacity of Drosophila but also enhances the diversity and uniformity of their intestinal microbiota. This demonstrates SAA's regulatory actions on Drosophila microbial community structure.