日粮中高糖高脂对团头鲂肝脏及肠道微生物菌群组成的影响

Effects of high-fat-high-carbohydrate diet on liver and composition of gut microbiota in blunt snout bream

为探讨日粮中高糖高脂对团头鲂肝脏及肠道微生物菌群组成的影响,分别采用组织学方法和16S rRNA宏基因组测序的方法对其进行研究。结果显示,高糖高脂连续饲喂8周后,团头鲂肝细胞呈不规则排列,肝细胞空泡化及细胞核偏移。试验构建了6个测序文库,获得了175 820条高质量序列和588个OTUs。在门水平上,试验组(高糖高脂)和对照组鱼肠道微生物菌群中,相对丰度最高的前4种分别为梭杆菌门(Fusobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和变形菌门(Proteobacteria),其中试验组的梭杆菌门和变形菌门的相对丰度高于对照组,而厚壁菌门和拟杆菌门低于对照组。在属水平上,各组主要菌群相对丰度也有所不同,其中试验组Clostridium、Romboutsia和Macellibacteroides的相对丰度高于对照组,分别是对照组的2、6和2倍,而Porphyromonadaceae和Aeromonas相对丰度低于试验组。核心菌群和特有菌群分析发现,对照组和试验组共有OTUs为82个,试验组特有OTUs为26个,主要菌门为变形菌门(57.69%)、酸杆菌门(Acidobacteria)(11.54%)和厚壁菌门(11.54%)。这些研究结果表明,高糖高脂饲料投喂团头鲂8周后,对团头鲂肝脏组织产生明显损伤,并对其肠道内容物微生物的菌群组成与结构产生影响,引起肠道菌群失调,进而可能对宿主的健康产生影响。

To explore the effects of high-fat-high-carbohydrate diet on the liver and composition of gut microbiota in blunt snout bream,the histology method and meta-analysis of 16S rRNA gene sequencing was conducted in this study.The blunt snout bream hepatocytes appeared to be disordered in orientation,nuclear migration and vacuolization after feeding with high-fat-high-carbohydrate diet for eight weeks.A total of 175 820 quality-filtered sequences and 588 OTUs(operational taxonomic units)from six 16S rRNA libraries were obtained.The most abundant taxa(top 4)of bacteria at phylum level in both the control and experimental group(high-fat-high-carbohydrate diet)were Fusobacteria,Firmicutes,Bacteroidetes and Proteobacteria.Among these bacteria,the relative abundance of Fusobacteria and Proteobacteria were higher,while the relative abundance of Firmicutes and Bacteroidetes were lower in the experimental group than that in control group.At the genus level,the relative abundance of the main microbiome in the two groups was different.The Clostridium,Romboutsia and Macellibacteroides in the experimental group were two,six and two-fold of the control group,respectively,while the Porphyromonadaceae and Aeromonas were lower in the experimental group.Analysis of unique and shared bacterial flora showed that the control and experimental group shared 82 OTUs.Twenty six OTUs were unique in the experimental group and the most abundant phyla of the unique OTUs were Proteobacteria(57.69%),Acidobacteria(11.54%)and Firmicutes(11.54%).Collectively,these results indicated that high-fat-high-carbohydrate diet fed for certain days could induce serious injury in the liver tissue of blunt snout bream,influence the composition of gut microbiota,and cause imbalance of intestinal flora,which would be bad for the health of their host.