牛磺酸对卵形鲳鲹肠道微生物及免疫功能的影响

Effect of taurine on intestinal microbes and immune function in golden pompano(Trachinotus ovatus)

为了探讨牛磺酸对卵形鲳鲹(Trachinotus ovatus)肠道微生物菌群结构和免疫功能的影响,试验以鱼粉、发酵豆粕和玉米蛋白粉为基础蛋白源配制了牛磺酸质量分数分别为1.3 g·kg^(-1)(T0)、4.4 g·kg^(-1)(T1)、7.4 g·kg^(-1)(T2)、10.5 g·kg^(-1)(T3)、12.7 g·kg^(-1)(T4)的等氮等脂饲料。将750尾卵形鲳鲹(81.0±0.5)g随机分为5组(每组150尾,分为3个平行),试验为期56 d。高通量测序结果显示在卵形鲳鲹肠道内共获得87707条序列,能够注释到数据库的OTUs数目为5130(95.32%),在门水平上,变形菌门、软壁菌门、螺旋体门为优势菌群。Alpha和Beta多样性分析表明,T2组中的肠道微生物丰富度和多样性最低,T1和T4组间物种组成差异较大(P<0.05)。随外源性牛磺酸的添加,血清溶菌酶活性显著提高,补体C4和免疫球蛋白含量显著增加(P<0.05);各试验组ToTLR-1、ToTLR-2、ToTNF-α和ToIL-1β基因表达量显著降低(P<0.05);T1、T2和T4组的ToNFkB P65基因表达量显著低于对照组(P<0.05);T3和T4组ToIL-10基因表达量显著高于对照组(P<0.05)。该试验结果显示,外源牛磺酸对卵形鲳鲹肠道微生物菌群和免疫功能具有显著影响。

In order to investigate the effects of taurine on the intestinal microflora structure and immune function of Trachinotus ovatus,we used fish meal,fermented soybean meal and corn gluten meal as the basic protein sources to prepare the nitrogen and fat feed with taurine contents of 1.3 g·kg^(-1)(T0),4.4 g·kg^(-1)(T1),7.4 g·kg^(-1)(T2),10.5 g·kg^(-1)(T3),12.7 g·kg^(-1)(T4),respectively.Seven hundred and fifty individuals of T.ovatus with an average body mass of(80.0±0.5)g were randomly devided into five groups with three replicates of fifty fish,and the experiment lasted 56 d.Sequencing results show that a total of 87707 sequences had been obtained in the intestine of T.ovatus.The number of OTUs that can be annotated to the database was 5130(95.32%).At phylum level,Proteobacteria,Tenericutes and Spirochaetes were the predominant phyla.Alpha diversity and beta diversity analyses show that the richness and diversity of intestinal microbial in T2 group were the lowest and the species composition was significantly different between T1 and T4 groups(P<0.05).The serum lysozyme activity,C4,and Ig increased significantly with the addition of exogenous taurine(P<0.05).The expression of ToTLR-1,ToTLR-2,ToTNF-αand ToIL-1βin each group decreased significantly(P<0.05).The expression of ToNFkB P65 of T1,T2 and T4 groups was significantly lower than that of the control group(P<0.05),while the expression of ToIL-10 of T3 and T4 groups was significantly higher than that of control group(P<0.05).The results indicate that exogenous taurine has a significant impact on intestinal microflora and immune function.