Selenium-modified Hericium erinaceus polysaccharides improves intestinal immunity and ND vaccine responses in chickens

This study aimed to investigate the immunomodulatory effects of selenium-modified Hericium erinaceus polysaccharides on intestinal immunity and Newcastle disease (ND) vaccine responses in chickens. Selenium modification of HEP (SHEP) was confirmed via SEM, TEM, FT-IR, Monosaccharide composition, Molecular weight, stability, release assay and the selenium content of SHEP. In vitro , SHEP-M group significantly decreased ROS, CD86, IL-1β, IL-6 and TNF-α levels, and enhanced CD206 levels. In vivo , chickens immunized with Newcastle disease vaccine showed that 160 mg/kg SHEP significantly increased thymus, spleen, and bursa indices, as well as ND-HI antibody titers. SHEP enhanced CD4 + /CD8 + T cell proportions in peripheral blood/intestine, and elevated IL-4, IFN-γ, TLR4, and CCR9 levels. SHEP also improved jejunal villi, increased villus height, crypt depth, and VH/CD ratio. 16S analysis revealed SHEP increased the abundances of Bacteroides, Parabacteroides and Alistipes , and optimized the F/B ratio and intestinal flora structure. Collectively, SHEP may enhance immunity and offer insights for the development of novel polysaccharide formulations.