单一益生菌(屎肠球菌)介导的断奶仔猪肠道菌群变化规律

Changes Induced by Probiotic,Enterococcus faecium,in Gut Microbiota of Post-weaning Piglet

通过细菌16SrRNA基因的高通量测序,对断奶仔猪的肠道菌群结构和饲喂两株单一益生菌(屎肠球菌)后肠道菌群的变化情况和规律进行分析。结果显示,断奶仔猪肠道微生态中拟杆菌门Bacteroidetes和厚壁菌门Firmicutes的细菌所占比例分别为50.5%和42.2%,为绝对优势菌群。饲喂屎肠球菌后,肠道菌群的多样性和细菌丰度均增加;厚壁菌门Firmicutes,变形菌门Proteobacteria、无壁菌门Tenericutes、酸杆菌门Actidobacteria、芽单胞菌门Gemmatimonadetes、放线菌门Actinobacteria细菌的丰度明显上升,而拟杆菌门Bacteroidetes的细菌丰度则发生了明显下降。屎肠球菌所在的肠球菌属Enterococcus的比例虽由0.07%(对照组)上升至0.12%(SF1组)和0.14%(SF2组),但在肠道菌群中所占比例仍然很小,说明屎肠球菌对仔猪肠道微生态的作用主要是影响其他细菌的丰度和多样性进而改变菌群结构。与对照组相比,SF1组的上述菌群变化幅度高于SF2组,通过与3组仔猪生长性能数据的对比,上述菌群变化的幅度与仔猪生长性能提高的程度呈现正相关。

Using the 16S rRNA gene high through-put sequencing technique, the microbial composition of the gut microbiota in post-weaning piglets was characterized. The compositional alterations induced by two strains of Enterococcus faecium were studied. The resulting dominant species in the guts were found to be of Firmicutes and Bacteroidetes phyla with contribution rates of 50. 5% and 42.2%, respectively. The richness and diversity of the bacterial community increased after the E. faecium administration. The populations of 6 phyla （i. e. , Firmicutes, Proteobacteria, Tenericutes, Actidobacteria, Gemmatimonadetes, and Actinobacteria） were increased, while that of Bacteroidetes significantly declined. A low abundance of Enterococcus spp. was detected in the piglet guts. However, the increase was merely 0. 07% over control and 0. 12 over the treatment group, SF1, and 0. 14% over group SF2 after the feeding. Consequently, the primary effects induced by the probiotics, E. faecium strains, were contributed mainly to the changes on the richness and diversity, or the composition, of the gut microbes. It appeared that the positive results observed on the growth performances of the post-weaning piglets in the field experiment due to the introduction of the probiotics warned further attention.