The presence of healthy gut microbiota in the gastrointestinal tract of fish is important for the optimal function of gut, which plays a significant role in the host growth and health. The aim of the present study was to investigate the effect of dietary stress worry free (SWF®) on growth, feed utilization and disease resistance of hybrid sturgeon (Acipenser baerii x Acipenser schrenckii). Sturgeon were fed for three weeks with SWF® supplemented or basal diet. The weight gain and FCR of sturgeon fed on the diet supplemented with SWF® were significantly improved (P<0.05). SWF® supplemented diet provoked an increase in the resistance of sturgeon against A. veronii Hm091 (P=0.09). In terms of gut microbiota, the number of total bacteria, Fusobacteria, Firmicutes, and Proteobacteria were increased significantly in the SWF® group (P<0.05), whereas significant reduction of Actinobacteria was observed in the gut of the SWF® group compared with the control group (P<0.01). Moreover, at the end of the experiment the gut microbiota of sturgeon, were colonized to germ-free (GF) zebrafish for three days. Results indicated that, the expression of growth promoter genes mTOR, MyoD and Myogenin was significantly higher in GF zebrafish colonized with gut microbiota of SWF® group of sturgeon. Furthermore, TGF-β was increased significantly in GF zebrafish colonized with gut microbiota from SWF® group (P<0.01), whereas the expression of TNF-α was significantly decreased (P<0.05). The expression of non-specific immune related genes DEFBL-1, C3a and Lysozyme was significantly increased in GF zebrafish colonized with gut microbiota of sturgeon fed on SWF® (P<0.05). Group of GF zebrafish colonized with gut microbiota of sturgeon fed on SWF® had significantly higher survival rate against A. veronii Hm091 (P<0.05). Our study suggests that, the gut microbiota induced by SWF® played a great role in growth and disease resistance of sturgeon using GF zebrafish model.

鱼的胃肠道中存在健康的肠道菌群对于肠道的最佳功能很重要，肠道的最佳功能在宿主的生长和健康中起着重要作用。本研究的目的是研究饮食压力无忧（SWF®）对杂交st鱼（Acipenser baerii x Acipenser schrenckii）的生长，饲料利用和抗病性的影响。用补充的或基础的饮食喂养fed鱼三个星期。补充了SWF®的日粮喂养的st鱼的体重增加和FCR显着改善（P <0.05）。补充SWF®的饮食引起st鱼对ver。veronii Hm091（P= 0.09）。就肠道菌群而言，SWF®组的总细菌，梭菌，坚定菌和变形杆菌的数量均显着增加（P <0.05），而与之相比，SWF®组的肠道中放线菌的数量则显着减少。对照组（P <0.01）。此外，在实验结束时，将st鱼的肠道菌群定植到无菌（GF）斑马鱼中三天。结果表明，生长在promoter鱼SWF®组肠道菌群中的GF斑马鱼中生长启动子基因mTOR，MyoD和Myogenin的表达明显升高。此外，SWF®组肠道菌群定殖的GF斑马鱼中TGF-β显着增加（P<0.01），而TNF-α的表达则明显降低（P <0.05）。在以SWF®为食的st鱼肠道菌群定殖的GF斑马鱼中，非特异性免疫相关基因DEFBL-1，C3a和溶菌酶的表达显着增加（P <0.05）。与鲟鱼饲喂SWF®的肠道菌群定殖GF斑马鱼的组具有针对显著较高的存活率A.维罗纳Hm091（P <0.05）。我们的研究表明，使用GF斑马鱼模型，SWF®诱导的肠道菌群在st鱼的生长和抗病性中发挥了重要作用。