基于高通量测序的丁酸梭菌对肉鸡盲肠菌群结构的影响

Effect of Clostridium butyricum in feed on structures of cecal microbiota in broilers based on high-throughput sequencing

采用高通量测序技术分析饲料中添加丁酸梭菌对肉鸡盲肠菌群结构的影响。选用300羽1日龄肉鸡随机分成2组,每组6个重复,每个重复25羽鸡,分别饲喂基础日粮和基础日粮+丁酸梭菌3×10~7cfu·kg^(-1)的试验日粮。在42日龄阶段称量体质量后每个重复取3羽公鸡用于采集盲肠内容物,提取其基因组DNA,用特异性引物扩增细菌16S rRNA基因V3-V4区,采用基于Illumina Miseq测序平台对细菌16S rRNA基因进行测序分析。结果表明,添加丁酸梭菌可以显著地降低肉鸡的料肉比(P<0.05)。肉鸡盲肠中细菌主要是硬壁菌门、拟杆菌门、变形菌门和软壁菌门;在门的水平上,丁酸梭菌处理具有降低硬壁菌门丰度、增加拟杆菌门丰度的趋势。在属的水平上,瘤胃菌属(Ruminococcaceae_uncultured)、粪栖杆菌属(Faecalibacterium)、别样杆菌属(Alistipes)、毛螺菌属(Lachnospiraceae_incertae_sedis)是肉鸡盲肠中的主要优势菌属;丁酸梭菌处理使肉鸡盲肠中粪栖杆菌(Faecalibacterium)、别样杆菌(Alistipes)、类杆菌属(Bacteroides)、Phascolarctobacterium和丁酸梭菌(Butyricicoccus)相对丰度显著升高(P<0.05),毛螺菌属(包括Lachnospiraceae_incertae_sedis和Lachnospiraceae_unclassified)、理研菌属(Rikenella)、链球菌(Streptococcus)和Blautia属相对丰度显著降低(P<0.05),其中丰度显著升高菌群为主要的短链脂肪酸生成菌。由此表明,日粮中添加丁酸梭菌可降低肉鸡的料肉比,增加盲肠中产短链脂肪酸菌群的丰度。

The aim of this study was to investigate the effects of Clostridium butyricum（CB） on cecal microbiota in broiler chickens based on high-throughput sequencing. A total of 300 one-day-old birds were randomly allotted to 2groups,representing control（basal diet） and CB-treated group（basal diet ＋ 3 × 10^7cfu·kg^-1CB）,6 replications per group with 25 chickens per replication. All chickens were weighted and cecal contents were collected from 3 male chickens per replication to extract genomicDNA after a 42-d treatment. The V3 and V4 regions in 16 S rRNA gene of bacteria were amplified and analyzed based on Illumine Miseq sequencing. Results showed that the feed to gain ratiosignificantly reduced（P〈0. 05） in CB treatment. Among all bacterial groups revealed by the interpretable sequences,Firmicutes,Bacteroidetes,Proteobacteria and Tenericutes were the predominant phylum in cecum of chickens. It indicated the trend that the relative abundance of Firmicutes decreased by CB treatment,whereas Bacteroidetes increased. At the genera level,Ruminococcaceae uncultured,Faecalibacterium,Alistipes,Lachnospiraceae_incertae_sedis dominated in cecum. Compared with the control group,administration of CB increased the relative abundance of Faecalibacterium,Alistipes,Bacteroides,Phascolarctobacterium and Butyricicoccus（P〈0. 05）,but decreased the relative abundance of Lachnospiraceae_incertae_sedis,Lachnospiraceae_unclassified,Rikenella,Streptococcus and Blautia（P〈0. 05）. Interestingly,the genera of increasing abundance were major bacteria which produce short-chain fatty acids（SCFAs） in cecum and large intestine. These findings suggested that the addition of CB to diet decreased the feed to gain ratio but increased the abundance of bacteria producing SCFAs in cecum of broiler chickens.