Dietary Lauric Acid and Its Derivatives in Aquaculture Nutrition: Sources, Mechanisms of Action, and Physiological Effects
Lauric acid (LA), a medium-chain fatty acid abundant in coconut oil and Hermetia illucens larvae, has been reported to promote growth performance and exhibit antimicrobial and immunostimulatory properties. This review examines current studies on its effects on growth performance, intestinal health, microbiota modulation, and immune responses in aquatic species. Studies in finfish and crustaceans were evaluated according to the LA source, distinguishing purified LA, LA derivatives such as monoglycerides, and LA rich ingredients, when considering LA rich ingredients. Overall, LA was associated with changes in growth performance, feed efficiency, survival, intestinal morphology, gut microbiota, and immune and antioxidant responses, although effects varied with source, dose, species, and experimental conditions. Reported effects include increased villus height and goblet cell density, modulation of gut microbiota, altered cytokine expression, increased antioxidant enzyme activity, and reduced lipid peroxidation. Overall, LA appears to be a promising functional component in aquafeeds for finfish and crustacean species. Nevertheless, inconsistent experimental designs, differences in LA sources, and species-specific responses make direct comparisons among studies difficult. Further studies that use standardized experimental protocols, including consistent LA sources, dietary inclusion levels, trial durations and evaluation criteria, are needed to define optimal inclusion levels in different aquatic species.