• Mixed fungal polysaccharides (FP) at 400 mg/kg significantly improved intestinal morphology in broilers, increasing villus height and VH/CD ratio while reducing crypt depth across duodenum, jejunum, and ileum.
• The 400 mg/kg FP treatment enhanced antioxidant capacity by elevating T-AOC, T-SOD, and GSH-Px activities and upregulating Nrf2/HO-1 pathway genes (HO-1, NQO1, CAT, Nrf2).
• The synergistic combination of Ganoderma lucidum polysaccharide (GLP) and lentinan (LNT) at a 1:1 ratio offers a promising natural alternative to antibiotics for improving poultry gut health and performance.
• These findings support the use of mixed fungal polysaccharides as feed additives to mitigate oxidative stress and promote intestinal health in intensive poultry production.