Lysophospholipids coordinate glyco-lipid metabolism in Litopenaeus vannamei to enhance feed efficiency under low-fishmeal diets

This study was conducted to evaluate whether lysophospholipids can improve the utilization efficiency of Litopenaeus vannamei to low-fishmeal and low-lipid diets. Juveniles (≈0.29 g) were reared for 8 weeks on five isonitrogenous diets: a positive control with 7% fishmeal and 8.5% crude lipid, a low-lipid control (7.5% crude lipid) in which fish oil was removed, and the latter supplemented with 0.025, 0.05, or 0.10% LPLs. Survival was unaffected. Inclusion of 0.025–0.05% LPLs increased final body mass and growth rate, reduced feed conversion ratio, and enhanced protein deposition. Digestive capacity improved via higher amylase and trypsin activities and better intestinal architecture. Antioxidant and immune status were strengthened (higher superoxide dismutase, catalase, glutathione peroxidase; lower malondialdehyde) alongside up-regulation of peritrophic-membrane and anti-inflammatory factors. The intestinal microbiota shifted toward higher Bacteroidota and Actinobacteriota and lower Proteobacteria, with reduced relative abundance of Vibrio. In the hepatopancreas, LPLs coordinated glycolipid metabolism, elevating activities and transcripts of enzymes for lipid catabolism and glycolysis, lowering serum glucose, triglycerides, and cholesterol, reducing lipid droplet deposition, and increasing glycogen storage. At 0.10% the growth benefit attenuated, indicating a narrow optimum. LPLs at 0.025–0.05% thus offer a practical strategy to unlock feed efficiency and reinforce defensive capacity in shrimp fed low-fishmeal and low-lipid diets.