Effects of Enteromorpha polysaccharide-selenium on oxidative stress, immune stress, and intestinal health in broilers

Purpose Intensive and large-scale poultry farming often induces oxidative and immune stress in broilers, compromising their health and production performance. In this study, a lipopolysaccharide (LPS) challenge model was established to induce oxidative and immune stress, and Enteromorpha polysaccharide-selenium (EP-Se) was evaluated as an organic selenium alternative to sodium selenite in broiler diets. Methods A total of 192 one-day-old male Arbor Acres broilers were randomly assigned to four dietary treatments ( n = 6 replicates per treatment, 8 birds per replicate): (1) SS, basal diet supplemented with 0.3 mg/kg selenium from sodium selenite; (2) LPS, SS diet plus LPS challenge; (3) EP-Se, basal diet supplemented with 0.3 mg/kg selenium from EP-Se; and (4) LSE, EP-Se diet plus LPS challenge. The experimental period lasted 21 days. Results EP-Se supplementation significantly increased body weight, average daily gain (ADG), and average daily feed intake (ADFI) ( P < 0.05), mitigating LPS-induced growth suppression. It enhanced antioxidant capacity by reducing malondialdehyde (MDA) levels, upregulating antioxidant gene expression, and increasing antioxidant enzyme activity ( P < 0.05). EP-Se also alleviated LPS-induced inflammation by inhibiting activation of the TLR/NF-κB signaling pathway and reducing intestinal proinflammatory cytokine levels ( P < 0.05). Furthermore, EP-Se improved intestinal health by modulating gut microbiota composition and increasing short-chain fatty acid concentrations ( P < 0.05). Conclusion Collectively, EP-Se exhibits potent antioxidant and anti-inflammatory effects and promotes gut health in LPS-challenged broilers. These findings provide a theoretical basis for developing EP-Se as a functional organic selenium additive for poultry feed.