Molecular Regulation of Intermediary Metabolism Focusing on Utilization of Dietary Carbohydrates

Dietary carbohydrate-to-protein ratio influences growth performance, hepatic health and dynamic of gut microbiota in atlantic salmon (Salmo salar)

“…The red Sirius stain did not show deposition of collagen fiber in the hepatic parenchyma in the HC/LP, supporting no histological damage in liver tissue in fish fed the carbohydrate-rich diet. In line with our findings, previous studies have reported feeding digestible carbohydrates-rich diets to carnivorous fish species lead to an increase in lipid deposition in liver and HSI ( Hemre et al., 2002 ; Panserat (2009) ; Enes et al., 2011 ; Gatesoupe et al., 2014 ; Limbu et al., 2020 ). In the present study, dietary lipids are unlikely to be the factor causing the increment in hepatic lipid deposition of fish fed the carbohydrates-rich diet, since this experimental group exhibit significant lower feed intake and experimental diets had close levels in lipid content.…”

“…As part of the same study, we have further analyzed the effect of feeding 3 graded levels of digestible carbohydrate in the form of a low carbohydrate-to-high protein diet (LC/HP, 0% wheat starch), a medium carbohydrate-to-medium protein diet (MC/MP, 15% wheat starch) or a high carbohydrate-to-low protein diet (HC/LP, 30% wheat starch) to Atlantic salmon on distal intestine digesta microbiota communities over 3 different sampling times (i.e., weeks 4, 8 and 12), during a 12-week feeding trial. Secondary objectives were to determine whether the nutritional challenge exerts an effect in growth performance, hepatic steatosis, and hepatic lipid synthesis in fish, since previous works have described carnivorous fish fed carbohydrate rich meals exhibit reduced growth performance and/or “fatty liver” condition due to neolipogenesis, which appears to be consequence of a long-term effect of high-carbohydrate diet-associated persistent postprandial hyperglycemia ( Hemre et al., 2002 ; Panserat (2009) ; Enes et al., 2011 ; Gatesoupe et al., 2014 ).…”

Glucose metabolism and gene expression in juvenile zebrafish (Danio rerio) challenged with a high carbohydrate diet: effects of an acute glucose stimulus during late embryonic life

“…The increase in the expression level of HK1 and the simultaneous decrease in the expression of PEPCK suggest a higher capacity for glucose phosphorylation as well as a lower glucose production, and thus, the possibility of glucose stimulus to ‘programme’ these two major pathways towards a more efficient control of glucose homeostasis when subjected again to hyperglycaemic conditions. Although not fully understood, the persistent hyperglycaemia observed in several fish species after high carbohydrate intakes has been ascribed to an atypical regulation of hepatic gluconeogenesis ( 56 , 57 ) . More specifically, in contrast to mammals, fish transcriptional regulation of gluconeogenic genes does not seem to be down-regulated by high dietary carbohydrate intakes ( 12 , 57 – 59 ) .…”

Putative imbalanced amino acid metabolism in rainbow trout long term fed a plant-based diet as revealed by 1H-NMR metabolomics

“…However, metabolic pathways are often studied separately – energy v. nutrient metabolism or protein v. lipid metabolism – and an integrated analysis of these different metabolic pathways is rarely conducted ( 16 ) . Furthermore, there is a growing interest in a non-targeted metabolism analysis to decipher the main drivers of fish metabolism and the potential interconnection between pathways under non-limiting farming conditions ( 17 ) . Significant progress on the impact of P-based diets on nutrition and metabolism has been achieved by using various targeted and non-targeted omic approaches such as transcriptomics and proteomics ( 4 , 7 , 8 , 18 ) .…”