Black solider fly larvae (BSFL) and their oils (BSFLO) are receiving increasing attention as sustainable ingredients in fish feeds, but mostly as replacements to marine sources. There were two aims to this study; in exp. 1, soybean meal (SBM)-based diets were formulated to contain BSFL as supplements at 0 (SBM), 8 (SBM+BSFL_low) or 16% (SBM+BSFL_high) with a control diet being fishmeal-based (FM). In exp. 2, diets included only fish oil (FO), soybean oil (SBO), BSFLO or BSFLO + bile acid (BA), and all lipid sources were added at 16%. Both experiments were run at the same time and fed to rainbow trout (32g) with each treatment being triplicated. After 10 weeks the fish were sampled for liver and distal intestine histology, expression of genes responsible for inflammation in the intestine and kidneys, and serum peroxidase and lysozyme activities. In exp. 1, supplementations of BSFL effectively prevented SBM-induced intestinal enteritis, down-regulated intestinal prostaglandin and interferon regulatory factor 1 (IRF-1), while the SBM+BSFL_high diet significantly increased serum lysozyme activity. In exp. 2, BSFLO caused no histomorphological change to the liver or intestine, but kidney interluekin-8, tumor necrosis factor and IRF-1 were significantly upregulated along with significantly higher serum peroxidase activity. The inclusion of BA in the BSFLO diets significantly upregulated intestinal prostaglandin gene expression. Overall, BSFL supplementations of 8 or 16% prevented SBM-induced intestinal enteritis based on histological observations, which was supported by a down-regulation in pro-inflammatory genes and enhanced innate immunity. Meanwhile, the use of BSFLO showed some immunological benefits. Therefore, these sustainable resources are recommended in the diets of rainbow trout, especially when using elevated levels of plant-based proteins.

黑水虻幼虫 (BSFL) 及其油 (BSFLO) 作为鱼饲料中的可持续成分越来越受到关注，但主要是作为海洋来源的替代品。这项研究有两个目的；在实验中。 1、基于豆粕（SBM）的日粮配制为含有 0（SBM）、8​​（SBM+BSFL_低）或 16%（SBM+BSFL_高）的 BSFL 作为补充剂，对照日粮为鱼粉（FM） 。在实验中。 2、日粮仅包含鱼油（FO）、豆油（SBO）、BSFLO或BSFLO+胆汁酸（BA），并且所有脂质源均添加16%。两个实验同时进行，并喂给虹鳟鱼（32g），每个处理重复三次。 10周后，对鱼进行肝脏和远端肠道组织学检查、负责肠道和肾脏炎症的基因表达以及血清过氧化物酶和溶菌酶活性。在实验中。如图1所示，补充BSFL有效预防SBM引起的肠道肠炎，下调肠道前列腺素和干扰素调节因子1（ IRF-1 ），而SBM+BSFL_高饮食显着增加血清溶菌酶活性。在实验中。 2、BSFLO对肝脏或肠道没有造成组织形态学变化，但肾脏白介素8、肿瘤坏死因子和IRF-1显着上调，血清过氧化物酶活性显着升高。 BSFLO 饮食中添加 BA 显着上调肠道前列腺素基因表达。总体而言，根据组织学观察，补充 8% 或 16% 的 BSFL 可以预防 SBM 诱导的肠炎，促炎基因下调和先天免疫增强也支持了这一点。 同时，BSFLO 的使用显示出一些免疫学益处。因此，建议在虹鳟鱼的饮食中使用这些可持续资源，特别是在使用高水平的植物蛋白时。