Creatine ameliorates the adverse effects of high-fat diet on hepatic lipid metabolism, intestinal health, muscle growth and flesh quality in juvenile largemouth bass ().

With the widespread use of high-fat diets (HFD) in aquaculture, the adverse effects of HFD on farmed fish are becoming increasingly apparent. Creatine has shown potential as a green feed additive in farmed fish; however, the potential of dietary creatine to attenuate adverse effects caused by high-fat diets remains poorly understood. To address such gaps, this study was conducted to investigate the mitigating effect of dietary creatine on HFD-induced disturbance on growth performance, hepatic lipid metabolism, intestinal health and muscle quality of juvenile largemouth bass. Three diets were formulated: a control diet (10·20 % lipid), a high-fat diet (HFD, 18·31 % lipid) and HFD with 2 % creatine (HFD + creatine). Juvenile largemouth bass (3·73 (sem 0·01) g) were randomly assigned to three diets for 10 weeks. The key findings were as follows: (1) the expression of muscle growth-related genes and proteins was stimulated by dietary creatine, which contributes to ameliorate the adverse effects of HFD on growth performance; (2) dietary creatine alleviates HFD-induced adverse effects on intestinal health by improving intestinal health, which also enhances feed utilisation efficiency; (3) dietary creatine causes excessive lipid deposition, mainly lipolysis and -oxidation. Notably, this study also reveals a previously undisclosed effect of creatine supplementation on improving muscle quality. Together, for the first time from a comprehensive multiorgan or tissue perspective, our study provides a feasible approach for developing appropriate nutritional strategies to alleviate the adverse effects of HFD on farmed fish, based on creatine supplementation.