Lipidomic Characterization of Muscle and Head of <i>Litopenaeus vannamei</i> Exposed to <i>Lactococcus lactis</i> D1813 at Varied Levels of Salinity and Dissolved Oxygen

The present study examined the impacts of <i>Lactococcus lactis</i> D1813, salinity (8 and 25 ppt), and dissolved oxygen (DO) concentrations of 8.5 and 3.5 mg/L on <i>Litopenaeus vannamei</i> muscle and head lipidomic profile. The muscle and head were examined using liquid chromatography-mass spectrometry (LC-MS/MS) for lipidomic nutrient profiling. The lipidomic profiling revealed the primary nutritional metabolites in <i>L. vannamei</i> muscle and head, which are composed of glycerophospholipids, sphingolipids, sterols, and saturated fatty acids. Huang head had the most glycerophospholipids and sterols, including PC (12:0/18:2), PC (18:0/20:4), PC (16:1/22:6), PC (10:1e/20:4), PC (33:0/18:2), Cer (d14:1/20:0), SM (t18:1/22:4), and SM (d18:0/16:1). Conversely, the T3BS head group had a much greater proportion of sphingolipids and saturated fatty acids, including Cer (d14:1/20:0), SM (t18:1/22:4), SM (d18:0/16:1), SM (d18:1/18:3), and butyric acid, stearic acid, myristic acid, arachidic acid, and lauric acid (<i>p</i> < 0.05). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated the significant enrichment of glycerophospholipid metabolism, sphingolipid metabolism, glycerolipid metabolism, linolenic acid metabolism, and alpha-linolenic acid metabolism in T3BS muscle and head. The findings unequivocally demonstrate that the supplement of <i>L. lactis</i> D1813 under 25 ppt salinity and 3.5 mg/L DO levels significantly raises the content of sphingolipids and saturated fatty acids and enriches the metabolic pathways of linolenic acid and alpha-linolenic acid in <i>L. vannamei</i>. The results indicated that <i>L. lactis</i> D1813 could be used as an effective probiotic to enhance shrimp tolerance and nutritional quality in aquaculture systems under environmental stress conditions. Also, a more desirable lipid profile renders them beneficial to human health, particularly cardiovascular health and brain function. Additional research can be done to assess the therapeutic advantages of <i>L. vannamei</i>-derived lipids in humans regarding cardiovascular health, cancer, and brain functioning.