Dietary oils modulate inflammatory and oxidative responses in pigs: Associations with hepatic gene expression

Pigs are valuable animal models for metabolism. The impact of fatty acids (FAs) on lipid metabolism and inflammatory responses must be considered when analyzing the types of FAs present in edible oils. This study aimed to evaluate how diets containing soybean oil (SO), canola oil (CO), or fish oil (FO) influence cytokine levels and oxidative stress in liver and blood serum, reflecting local and systemic inflammation. Additionally, correlations with hepatic gene expression were assessed through weighted gene co-expression analysis. Twenty-seven male pigs were fed soybean meal and corn-based diets supplemented with 3% SO, CO, or FO for 98 days. Cytokines, including interleukin (IL)-10, interferon (IFN)-γ, IL-1β, IL-6, IL-18, and tumor necrosis factor (TNF)-α, were quantified in serum and liver using Enzyme-Linked Immunosorbent Assay (ELISA). Oxidative status in serum was evaluated using the ORAC assay and hypochlorous acid scavenging capacity. The CO diet increased IFN-γ in liver tissue and enhanced hypochlorous acid scavenging capacity, while the SO diet elevated IL-10 levels. Gene co-expression analysis revealed associations between cytokine levels and hepatic gene modules. The SO diet correlated positively with modules linked to IL-10 and TNF-α. The CO diet was associated with increased IFN-γ and decreased IL-6 and IL-18. The FO diet was negatively correlated with TNF-α. These results suggest that dietary oils modulate inflammatory and oxidative responses in pigs, with distinct patterns depending on fatty acid composition. The findings contribute to understanding how specific lipid profiles influence immune regulation and oxidative balance in metabolic studies using swine models.