Lauric-acid-rich Hermetia illucens meal modulates lipid metabolism in the liver and the fatty acid profile in piglet tissues

Abstract

This study investigated whether a diet rich in lauric acid, based on Hermetia illucens (HI) larvae meal, would induce measurable changes in lipid-related metabolic pathways in the liver and in the fatty acid composition of tissues. Twenty-four weaned piglets were assigned to three dietary groups: control (0% HI), 2.5% HI, and 5% HI. Multilevel analyses, including histology, biochemical assays, fatty acid profiling, and gene expression, were performed to assess liver function and metabolic adaptations of animal organisms. Dietary HI markedly reshaped the tissue lipid composition, increasing the levels of saturated fatty acids (SFA) and reducing polyunsaturated fatty acids (PUFA) in both muscle and adipose tissue (P < 0.001), with strong correlations with the amount of dietary lauric acid (C12:0). Despite these systemic changes, liver enzyme activity and oxidative stress markers remained unchanged, indicating the preservation of hepatic function. Histological analysis revealed a significant reduction in hepatic collagen content (P < 0.001), suggesting extracellular matrix remodeling, and a tendency toward increased glycogen accumulation (P = 0.055), indicative of altered substrate utilization. At the molecular level, HI supplementation modulated the expression of genes associated with cholesterol metabolism and cellular energy balance, including CYP7A1, DHCR24, and PRPS2. Although most transcriptional changes were modest, the combined biochemical, histological, and lipidomic data suggested coordinated metabolic adaptations. Collectively, these findings suggest that dietary inclusion of lauric-acid-rich Hermetia illucens larvae meal is associated with adaptive changes in hepatic metabolism, altered fatty acid composition, reduced collagen deposition, and changes in tissue lipid distribution, without evidence of hepatic dysfunction or oxidative imbalance. These results indicate that HI larvae meal may influence hepatic metabolism and tissue lipid composition, with potential implications for animal physiology and meat quality.