Effects of the type of dietary non‐protein energy source on the size and composition of the total body bile acid pool, on faecal bile acid loss and on bile acid synthesis were investigated in rainbow trout. Two diets were formulated (similar DP:DE ratio) that differed in the inclusion of either maize starch (Starch) or rapeseed oil (Fat) as main non‐protein source. Fish were fed to satiation for 44 days. Type of non‐protein energy source did not substantially affect the body bile acid pool composition. However, feeding the Starch diet resulted in a larger total body bile acid pool size compared with the Fat diet, and this despite enhanced faecal bile acid loss when feeding the Starch diet that was related to more faeces being produced. Bile acid synthesis in fish fed the Starch diet was more than two times higher compared with fish fed the Fat diet. The difference in body bile acid pool size between diets suggests upregulation of bile acid synthesis in fish fed the Starch diet beyond the level needed to compensate for the higher faecal bile acid loss and/or downregulation of bile acid synthesis in fish fed the Fat diet. The underlying mechanisms for this difference in synthesis need further investigation.

中文翻译：

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膳食非蛋白质能源类型（淀粉与脂肪）对虹鳟鱼（Oncorhynchus mykiss）体内胆汁酸池大小和组成，粪便胆汁酸损失和胆汁酸合成的影响

在虹鳟鱼中研究了膳食非蛋白质能源类型对全身胆汁酸池大小和组成，粪便胆汁酸损失和胆汁酸合成的影响。配制了两种日粮（DP：DE比例相似），不同之处在于玉米淀粉（淀粉）或菜籽油（脂肪）作为主要的非蛋白质来源。将鱼饱食44天。非蛋白质能源的类型基本不会影响人体胆汁酸池的组成。然而，与脂肪饮食相比，饲喂淀粉饮食会导致更大的全身胆汁酸池大小，尽管饲喂淀粉饮食会增加粪便中胆汁酸的损失，而这与产生更多的粪便有关。饲喂淀粉饮食的鱼的胆汁酸合成量比饲喂脂肪饮食的鱼高两倍以上。日粮之间的体内胆汁酸池大小的差异表明，饲喂淀粉饮食的鱼的胆汁酸合成上调超过了补偿高粪便胆汁酸损失所需的水平和/或饲喂脂肪饮食的鱼中胆汁酸合成的下调所需的水平。合成中这种差异的潜在机制有待进一步研究。