Dietary Inulin Modulates Intestinal Health and Muscle Nutritional Composition in Juvenile Silver Pomfret (Pampus argenteus)

The silver pomfret (Pampus argenteus) is a high-value marine food fish, but its aquaculture is limited by juvenile intestinal immaturity, characterized by impaired digestion, barrier dysfunction, and microbial dysbiosis. This study evaluated whether early-life dietary inulin could improve intestinal health and muscle nutritional composition. After an 8-week feeding trial, fish fed a 5 g/kg inulin-supplemented diet showed improved growth performance, as reflected by higher final body weight (+17.2%), WGR (+18.5%), and SGR (+6.4%) than the control group. These benefits were associated with enhanced intestinal morphology, increased α-amylase and lipase activities, upregulated expression of tight junction genes, and a remodeled gut microbiota. These gut-associated changes were accompanied by improved selected muscle compositional traits. Specifically, inulin supplementation enriched essential amino acids, including methionine and threonine, as well as flavor-related amino acids, such as glutamate, glycine, and serine. Meanwhile, the muscle lipid profile was also modified, as reflected by reduced levels of selected saturated fatty acids and increased levels of monounsaturated fatty acids, particularly oleic acid. Collectively, our findings suggest that early-life dietary supplementation with 5 g/kg inulin may support intestinal homeostasis-related indicators and improve selected muscle nutritional traits in farmed silver pomfret.