Abstract

Largemouth bass (Micropterus salmoides) were fed with three diets containing 6%, 12%, and 18% wheat starch for 70 days to examine their impacts on growth performance, glucose and lipid metabolisms, and liver and intestinal health. The results suggested that the 18% starch group inhibited the growth, and improved the hepatic glycogen content compared with the 6% and 12% starch groups (P < 0.05). High starch significantly improved the activities of glycolysis-related enzymes, hexokinase (HK), glucokinase (GK), phosphofructokinase (PFK), and pyruvate kinase (PK) (P < 0.05); promoted the mRNA expression of glycolysis-related phosphofructokinase (pfk); decreased the activities of gluconeogenesis-related enzymes, pyruvate carboxylase (PC), and phosphoenolpyruvate carboxykinase (PEPCK); and reduced the mRNA expression of gluconeogenesis-related fructose-1,6-bisphosphatase-1(fbp1) (P < 0.05). High starch reduced the hepatic mRNA expressions of bile acid metabolism–related cholesterol hydroxylase (cyp7a1) and small heterodimer partner (shp) (P < 0.05), increased the activity of hepatic fatty acid synthase (FAS) (P < 0.05), and reduced the hepatic mRNA expressions of lipid metabolism–related peroxisome proliferator–activated receptor α (ppar-α) and carnitine palmitoyltransferase 1α (cpt-1α) (P < 0.05). High starch promoted inflammation; significantly reduced the mRNA expressions of anti-inflammatory cytokines transforming growth factor-β1 (tgf-β1), interleukin-10 (il-10), and interleukin-11β (il-11β); and increased the mRNA expressions of pro-inflammatory cytokine tumor necrosis factor-α (tnf-α), interleukin-1β (il-1β), and interleukin-8 (il-8) in the liver and intestinal tract (P < 0.05). Additionally, high starch negatively influenced the intestinal microbiota, with the reduced relative abundance of Trichotes and Actinobacteria and the increased relative abundance of Firmicutes and Proteobacteria. In conclusion, low dietary wheat starch level (6%) was more profitable to the growth and health of M. salmoides, while high dietary starch level (12% and 18%) could regulate the glucose and lipid metabolisms, impair the liver and intestinal health, and thus decrease the growth performance of M. salmoides.

中文翻译：

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高膳食小麦淀粉对大口黑鲈幼鱼的生长性能、葡萄糖和脂质代谢、肝脏和肠道健康产生负调节

摘要

用含有 6%、12% 和 18% 小麦淀粉的三种饲料喂养大口黑鲈 ( Micropterus salmoides ) 70 天，以检查它们对生长性能、葡萄糖和脂质代谢以及肝脏和肠道健康的影响。结果表明，与6%和12%淀粉组相比，18%淀粉组抑制了生长，并提高了肝糖原含量（P  < 0.05）。高淀粉显着提高糖酵解相关酶己糖激酶（HK）、葡萄糖激酶（GK）、磷酸果糖激酶（PFK）和丙酮酸激酶（PK）的活性（P  < 0.05）；促进糖酵解相关磷酸果糖激酶 ( pfk ) mRNA 表达；降低糖异生相关酶、丙酮酸羧化酶（PC）和磷酸烯醇丙酮酸羧激酶（PEPCK）的活性；并降低糖异生相关果糖-1,6-双磷酸酶-1（fbp1）mRNA表达（P  < 0.05）。高淀粉含量降低了肝脏胆汁酸代谢相关胆固醇羟化酶（cyp7a1）和小异二聚体伙伴（shp） mRNA 的表达（P  < 0.05），增加了肝脂肪酸合成酶（ FAS ）的活性（P  < 0.05） ，肝脏脂质代谢相关过氧化物酶体增殖物激活受体 α ( ppar-α ) 和肉碱棕榈酰转移酶 1α ( cpt-1α ) mRNA 表达量 ( P  < 0.05)。高淀粉会促进炎症；显着降低抗炎细胞因子转化生长因子-β1 ( tgf-β1 )、白细胞介素-10 ( il-10 ) 和白细胞介素-11β ( il-11β ) 的 mRNA 表达；肝脏和肠道促炎细胞因子肿瘤坏死因子-α ( tnf-α )、白细胞介素-1β ( il-1β ) 和白细胞介素-8 ( il-8 ) mRNA 表达增加（ P  < 0.05） 。此外，高淀粉对肠道微生物群产生负面影响，毛菌门和放线菌门的相对丰度降低，厚壁菌门和变形菌门的相对丰度增加。综上所述，低饲料小麦淀粉水平（6%）更有利于大鲑鱼的生长和健康，而高饲料淀粉水平（12%和18%）可以调节糖脂代谢，损害肝脏和肠道。健康，从而降低鲑鱼的生长性能。