Dietary kelp meal alleviates feed starch intolerance of hybrid snakehead (Channa maculata ♀ × Channa argus ♂) by improving liver glycolipid metabolism and metabolite profile

Abstract

This study aimed to assess the influence of kelp meal (KM) on growth performance, hepatic glycogen accumulation, hepatic lipid deposition, as well as liver glucose-lipid metabolism in hybrid snakehead (Channa maculata ♀ × Channa argus ♂). A total of 810 juvenile hybrid snakeheads (11.4 ± 0.15 g) were randomly allocated into three groups (3 replicates per group) and given isontirogenous and isolipidic diets containing different levels of KM (10 %、15 %) for 60 days. The results showed that KM diets can significantly reduce liver glycogen accumulation and postprandial hyperglycemia in hybrid snakehead. This is accomplished by increasing levels of insulin secretion and decreasing glucagon levels, thereby increasing liver gluconeogenesis and inhibiting glycolysis. Additionally, there is a considerable reduction in liver lipid deposition with the KM diets. This is due to the lipid oxidative decomposition is promoted, and the liver lipid synthesis is inhibited. Meanwhile, KM diets enhance the body's lipid transport system. Omics analysis showed that the key to KM diets improving liver glycolipid metabolism of hybrid snakehead lies in regulating amino acid metabolism and lipid metabolism, and affecting changes in key metabolites of lipid metabolism. Among them, Jasmolone glucoside, L-Methionine S-oxide, Asparaginyl-Isoleucine and Didymin are key metabolites of great significance. Therefore, our study shows that 10 % KM diets can improve the glycolipid metabolism in hybrid snakehead liver, reduce lipid deposition, and alleviate hyperglycemia.