Lactobacillus plantarum (LPsca12) enhances growth phenotype and muscle nutrition in abalone (Haliotis discus hannai) by modulating microbial function and metabolism through the Amino Acid-Driven Gut-Muscle Axis

With the continuous expansion of abalone (Haliotis discus hannai) aquaculture, improving growth rate and muscle quality has become an increasingly important concern. Probiotic supplementation represents a promising strategy; however, the effects of probiotics on abalone remain poorly understood, particularly concerning their mechanisms of action on muscle physiology. This study employed a multi-omics investigation to explore the impact of the Lactobacillus plantarum (LPsca12) strain on hepatic metabolism and gut microbiota composition in abalone, and the potential associations between intestinal metabolites and short-chain fatty acids (SCFAs) in muscle. Our findings reveal that (I) probiotic supplementation induced notable shifts in gut microbiota composition, thereby enhancing abalone growth performance and reducing lipid accumulation by promoting hepatic lipid metabolism, (II) reshaped microbial community strongly linked to elevated concentrations of key amino acids in abalone, including L-leucine, L-isoleucine, L-valine, and L-arginine, which are considered potential precursors for SCFAs production, and (III) the elevated levels of SCFAs, such as acetate and propionate, in muscle tissue may activate the mTORC1 signaling pathway, thereby promoting protein synthesis and improving the nutritional status of abalone muscle. The results indicate that LPsca12 exerts beneficial effects on abalone by enhancing growth performance and improving lipid metabolism and promoting muscle nutritional status through an amino acid-driven gut–muscle axis.