Król Elżbieta, Douglas Alex, Tocher Douglas R, Crampton Viv O, Speakman John R, Secombes Christopher J, Martin Samuel A M
Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK.
Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK.
BMC Genomics. 2016 Feb 29;17:156. doi: 10.1186/s12864-016-2473-0.
The potential for alternative plant protein sources to replace limited marine ingredients in fish feeds is important for the future of the fish farming industry. However, plant ingredients in fish feeds contain antinutritional factors (ANFs) that can promote gut inflammation (enteritis) and compromise fish health. It is unknown whether enteritis induced by plant materials with notable differences in secondary metabolism is characterised by common or distinct gene expression patterns, and how using feeds with single vs mixed plant proteins may affect the gut transcriptome and fish performance. We used Atlantic salmon parr to investigate the transcriptome responses of distal gut to varying dietary levels (0-45%) of soy protein concentrate (SPC) and faba bean (Vicia faba) protein concentrate (BPC) following an 8-week feeding trial. Soybean meal (SBM) and fish meal (FM) were used as positive and negative controls for enteritis, respectively. Gene expression profiling was performed using a microarray platform developed and validated for Atlantic salmon.
Different plant protein materials (SPC, BPC and SBM) generated substantially different gut gene expression profiles, with relatively few transcriptomic alterations (genes, pathways and GO terms) common for all plant proteins used. When SPC and BPC were simultaneously included in the diet, they induced less extensive alterations of gut transcriptome than diets with either SPC or BPC singly, probably due to reduced levels of individual ANFs. The mixed plant protein diets were also associated with improved body composition of fish relative to the single plant protein diets, which may provide evidence for a link between the magnitude of changes in gut transcriptome and whole-animal performance.
Our results indicate that gut transcriptomic profiling provides a useful tool for testing the applicability of alternative protein sources for aquaculture feeds and designing diets with reduced impact of ANFs on fish health. Ultimately, understanding diet-gut interactions and intestinal homeostasis in farmed fish is important to maximise performance and to ensure that aquaculture continues to be a sustainable source of food for a growing world population.
替代植物蛋白源在鱼饲料中取代有限海洋成分的潜力对养鱼业的未来至关重要。然而，鱼饲料中的植物成分含有抗营养因子（ANFs），可促进肠道炎症（肠炎）并损害鱼的健康。尚不清楚由次生代谢有显著差异的植物材料诱导的肠炎是否具有共同或不同的基因表达模式，以及使用单一植物蛋白与混合植物蛋白的饲料如何影响肠道转录组和鱼的性能。我们使用大西洋鲑幼鱼，在进行8周喂养试验后，研究远端肠道对不同饮食水平（0 - 45%）的大豆浓缩蛋白（SPC）和蚕豆（Vicia faba）浓缩蛋白（BPC）的转录组反应。豆粕（SBM）和鱼粉（FM）分别用作肠炎的阳性和阴性对照。使用为大西洋鲑开发并验证的微阵列平台进行基因表达谱分析。
不同的植物蛋白材料（SPC、BPC和SBM）产生了截然不同的肠道基因表达谱，所有使用的植物蛋白共有的转录组改变（基因、途径和GO术语）相对较少。当SPC和BPC同时包含在日粮中时，它们诱导的肠道转录组改变比单独使用SPC或BPC的日粮要少，这可能是由于单个抗营养因子水平降低所致。与单一植物蛋白日粮相比，混合植物蛋白日粮还与鱼体组成的改善有关，这可能为肠道转录组变化幅度与全鱼性能之间的联系提供证据。
我们的结果表明，肠道转录组分析为测试替代蛋白源在水产养殖饲料中的适用性以及设计对抗营养因子对鱼健康影响较小的日粮提供了一个有用的工具。最终，了解养殖鱼类的饮食 - 肠道相互作用和肠道内稳态对于最大限度地提高性能以及确保水产养殖继续成为不断增长的世界人口可持续的食物来源至关重要。
