Gut microbiota impacts fish metabolism, nutrient utilization, and health. We know little about how temperature and diet interact with rainbow trout gut microbes. A total of 288 fish (average body weight: 45.6 g) fed four iso-caloric, -lipidic, and -nitrogenous diets comprised crude protein (40%) and lipid (20%) manufactured as 100% animal-based protein (AP) and blend of 50 fish oil (FO)/50 camelina oil (CO), 100% AP and 100% CO, 100% plant-based protein (PP) and blend of 50 FO/50 CO or 100% PP and 100% CO at 14 or 18°C water temperature. Gut content was analyzed using 16S rRNA gene and shotgun sequencing. Alpha-diversity did not change significantly. Regardless of diet, Tenericutes, Firmicutes, Proteobacteria, Spirochaetes, Bacteroidetes, and Actinobacteria dominated. At family level, Aeromonadaceae and Enterobacteriaceae dominated at 18°C, while Mycoplasmataceae dominated at 14°C. Moreover, genes relating to amino acid, carbohydrate, fat, and energy metabolisms and fatty acid biosynthesis significantly increased at 18°C. Functional profiles did not vary significantly among diets, except for a higher methionine and cysteine metabolism in fish fed plant ingredient compared animal diet, suggesting trout fed plant-derived protein mixed with CO could be as effective as those fed fish meals mixed with 50/50 FO and CO.

中文翻译：

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对虹鳟鱼、Oncorhynchus mykiss、在不同温度方案下饲喂植物蛋白和亚麻荠油的整个肠道微生物群的全基因组见解

肠道微生物群影响鱼类新陈代谢、营养利用和健康。我们对温度和饮食如何与虹鳟鱼肠道微生物相互作用知之甚少。总共 288 条鱼（平均体重：45.6 克）饲喂四种等热量、脂质和含氮饲料，其中包含粗蛋白 (40%) 和脂质 (20%)，制成为 100% 动物蛋白 (AP) 50 鱼油 (FO)/50 亚麻荠油 (CO)、100% AP 和 100% CO、100% 植物蛋白 (PP) 的混合物以及 50 FO/50 CO 或 100% PP 和 100% CO 的混合物水温为 14 或 18°C。使用 16S rRNA 基因和鸟枪法测序分析肠道内容物。 Alpha 多样性没有显着变化。无论饮食如何，特内里古门、厚壁菌门、变形菌门、螺旋体门、拟杆菌门和放线菌门占主导地位。在科水平上，气单胞菌科和肠杆菌科在 18°C 下占主导地位，而支原体科在 14°C 下占主导地位。此外，与氨基酸、碳水化合物、脂肪、能量代谢和脂肪酸生物合成相关的基因在18℃下显着增加。除了与动物饲料相比，饲喂植物成分的鱼的蛋氨酸和半胱氨酸代谢较高之外，不同日粮的功能特征没有显着差异，这表明饲喂与 CO 混合的植物源蛋白的鳟鱼可能与饲喂与 50/50 混合的鱼粉的鱼粉一样有效。 FO 和 CO。