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Simple Summary: An excessive carbohydrate content in diets can have a negative effect on fish growth. In this study, the effects of berberine supplementation in high-carbohydrate diets on the growth performance, glucose metabolism, bile acid synthesis, liver transcriptome, and intestinal flora of Nile tilapia were investigated. Conclusion: An appropriate amount of berberine can stimulate the synthesis of bile acids by changing the structure of the intestinal flora of tilapia, thus promoting glycolysis and inhibiting gluconeogenesis, then regulating the blood glucose, which is beneficial to the growth of tilapia. This provides the data to improve carbohydrate utilization in tilapia and support the development of high-carbohydrate diets in aquaculture. Berberine is an alkaloid used to treat diabetes. This experiment aimed to investigate the effects of berberine supplementation in high-carbohydrate diets on the growth performance, glucose metabolism, bile acid synthesis, liver transcriptome, and intestinal flora of Nile tilapia. The six dietary groups were the C group with 29% carbohydrate, the H group with 44% carbohydrate, and the HB1-HB4 groups supplemented with 25, 50, 75, and 100 mg/kg of berberine in group H. The results of the 8-week trial showed that compared to group C, the abundance of Bacteroidetes was increased in group HB2 (p < 0.05). The cholesterol-7α-hydroxylase (CYP7A1) and sterol-27-hydroxylase (CYP27A1) activities were decreased and the expression of FXR was increased in group HB4 (p < 0.05). The pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase (PEPCK) activities was decreased in group HB4 (p < 0.05). The liver transcriptome suggests that berberine affects carbohydrate metabolic pathways and primary bile acid synthesis pathways. In summary, berberine affects the glucose metabolism in tilapia by altering the intestinal flora structure, enriching differentially expressed genes (DEGs) in the bile acid pathway to stimulate bile acid production so that it promotes glycolysis and inhibits gluconeogenesis. Therefore, 100 mg/kg of berberine supplementation in high-carbohydrate diets is beneficial to tilapia. [ABSTRACT FROM AUTHOR]

Pacific white shrimp (Litopenaeus vannamei), the most cultured crustacean in the world, has become one of the key species in the international aquatic trade accounting for 11.96% of the total aquaculture production value in 2020. The development of the aquafeed industry, especially the large‐scale use of fish meal (FM) and fish oil, contributed to promoting the expansion of shrimp production. However, the supply of FM has fluctuated at about 5 million tons per year affected by the El Nino during the last decades. This finite supply in combination with continued demand contributes to high prices, prompting the development and use of alternative protein sources. This review contributes to the development of appropriate FM replacement strategies in shrimp feed and summarises the status of research on alternative protein sources, including plant, animal and single‐cell proteins in commercial feeds for Pacific white shrimp. Furthermore, several key aspects of nutritional balances were mentioned including amino acid profiles, fatty acid nutrients and trace elements in low FM diets as well as some easily overlooked concepts that deserve attention such as epigenetics, feed processing characteristics, animal growth stages, and shrimp species improvement. Also, the prospects of future research are proposed including the application of advanced technologies (16S rRNA sequencing, transcriptomics, proteomics and metabolomics), developments in the new feed additives, along with the optimisation of new protein sources and the establishment of a precise nutritional programming for shrimp. [ABSTRACT FROM AUTHOR]

Simple Summary: The ingestion of higher-lipid diets by fish could lead to excessive lipid deposition and metabolic disorders in vivo. This experiment analyzed the effects of steroidal saponins on hepatic glucose and lipid metabolism in hybrid grouper fed higher-lipid diets using a multi-omics approach. Data from grouper fed diets with 0% and 0.1% steroidal saponins show that 0.1% steroidal saponins inhibited glycogen synthesis, gluconeogenesis, and the arachidonic acid metabolism pathway and activated glycogenolysis, glycolysis, and the fatty acid β-oxidation pathway. This study provides a deeper insight into the glycolipid metabolic processes in the liver of grouper fed higher crude-lipid diets. An analysis of the extent of the effect of steroidal saponin addition on glucose and lipid metabolism in hybrid grouper liver was performed at the transcriptomic and metabolomic levels. Feeds (52% crude protein, 14% crude lipid) were prepared containing 0% (S0), 0.1% (S0.1), and 0.2% (S0.2) steroidal saponins. After eight weeks of feeding trial, compared to the S0 group, the activities of serum albumin, alanine aminotransferase, and aspartate transaminase were significantly lower and the activities of lysozyme, acid phosphatase, and alkaline phosphatase were significantly higher in the S0.1 group (p < 0.05). The superoxide dismutase, catalase, and glutathione peroxidase activities in the livers of the S0.1 group were significantly higher than those of the S0 group, while the malondialdehyde content was significantly lower than that of the S0 group (p < 0.05). There were forty-two differentially expressed genes and thirty-two differential metabolites associated with glucose and lipid metabolism enriched using KEGG and GO. In the S0 group, the expression of prostaglandin-endoperoxide synthase 1, prostaglandin E synthase 1, and thromboxane-2 synthase mRNA was significantly higher than in the S0.1 group (p < 0.05). The expression levels of genes in the S0 group were significantly higher than those in the S0.1 group (p < 0.05), including for glycogen synthase kinase, glucose-6-phosphatase catalytic subunit 2, fructose-1,6-bisphosphatase, phosphoenolpyruvate carboxykinase, glucose transporter 4, and malate dehydrogenase. The expression of mRNA such as fatty acid synthase, acetyl-CoA carboxylase, and sterol regulatory element-binding protein 1 was significantly lower in the S0.1 group than in the S0 group, while the expression of carnitine acyltransferase 1, acyl-CoA synthetase, and acyl-CoA dehydrogenase genes was significantly higher in the S0 group (p < 0.05). In summary, glycogen synthesis, gluconeogenesis, and the arachidonic acid metabolism pathway were inhibited by 0.1% steroidal saponins, and glycogenolysis, glycolysis, the tricarboxylic acid cycle, and the fatty acid β-oxidation pathway were activated. This study aims to provide a reference for the formulation of grouper feeds with a higher crude-lipid level. [ABSTRACT FROM AUTHOR]