屎肠球菌对哺乳期仔猪结肠微生物群落优势门属的影响

Effects of Enterococcus faecium on dominant phyla and genera of colonic microbial communities in suckling piglets

【目的】分析屎肠球菌(Enterococcus faecium)活菌对哺乳期仔猪结肠微生物群落优势门属的持续影响,为揭示益生菌调节仔猪肠道健康的作用机制及人为调控仔猪肠道微生物以促进其健康提供参考依据。【方法】给健康新生仔猪灌服无菌脱脂乳(对照组)或屎肠球菌制剂(益生菌组),持续灌服6 d,分别采集7和21日龄仔猪结肠内容物,提取总细菌DNA后进行PCR扩增,采用Illumina MiSeq高通量测序技术检测16S rRNA序列的V3～V4可变区,分析肠道微生物群落α多样性及其在门和属分类水平上的结构特点。【结果】给新生仔猪灌服屎肠球菌并不影响7和21日龄仔猪结肠微生物群落α多样性。与对照组相比,益生菌组7日龄仔猪结肠微生物群落优势门的相对丰度无显著变化(P>0.05,下同),21日龄仔猪拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)的相对丰度也无显著差异,但变形杆菌门(Proteobacteria)相对丰度呈显著增加趋势(P<0.05,下同);在属水平上,益生菌组7日龄仔猪结肠微生物群落中相对丰度变化明显的优势属均隶属于拟杆菌门,其中,普雷沃氏菌属(Prevotella)相对丰度显著增加,而拟杆菌属(Bacteroides)相对丰度极显著减少(P<0.01,下同),丁酸单胞菌属(Butyricimonas)相对丰度显著减少;21日龄仔猪结肠微生物群落中66.67%优势属的相对丰度呈减少趋势,其中以厚壁菌门4个属的变化尤其明显,即巨型球菌属(Megasphaera)相对丰度极显著减少,乳杆菌属(Lactobacillus)、产琥珀酸菌属(Succiniclasticum)和粪杆菌属(Faecalibacterium)相对丰度显著减少。【结论】新生仔猪口服屎肠球菌能对其结肠微生物群落优势门或属组成产生持续影响,表现为促进有益于结肠健康菌属的生长,而抑制具有潜在致病性菌属的增殖,为今后定向研究调控仔猪肠道健康的肠道共生微生物提供明确范围。

【Objective】The purpose of the study was to analyze the continuous influence of viable Enterococcus faecium on dominant phyla and genera of colonic microbial communities of suckling piglets,in order to provide scientific reference for fully understanding the mechanism of probiotics regulating intestinal health of piglets,and also regulating intestinal microorganism of piglets artificially to promote their health.【Method】Healthy newborn piglets were fed with sterile skim milk(as the control group),or E.faecium preparation(as the probiotic group)for continuously 6 d.Colonic contents of piglets aged 7 and 21 days were collected.Total DNA extraction and PCR amplification were performed successively.Illumina MiSeq high-throughput sequencing technology was utilized to detect the V3-V4 variable regions of 16S rRNA sequence.Finally,alpha diversity of intestinal microbial community and structural characteristics at phylum and genus level were analyzed.【Result】The results showed that no effect of E.faecium on alpha diversity of colonic microbial communities in 7-and 21-day-old piglets was observed.Compared with the control group,there was no significant change in relative abundance of the dominant phyla in colonic microbial communities of 7-day-old piglets in the probiotics group(P> 0.05,the same below).The relative abundance of Bacteroidetes and Firmicutes in 21-day-old piglets showed no significantly difference either,but the relative abundance of Proteobacteria was significantly increased(P<0.05,the same below).At the level of genus,the dominant genera whose relative abundance changed obviously in the colonic microbial communities in probiotics group of 7-day-old piglets were all belonging to phylum Bacteroidetes.Of which,the relative abundance of genus Prevotella increased remarkably.In contrast,the relative abundant of Bacteroides decreased extremely(P<0.01,the same below),and Butyricimonas reduced significantly.The relative abundance of 66.67% dominant genera in the colonic microbial communities of 21-day-old piglets showed a decreasing trend,especially in the four genera of phylum Firmicutes.The abundance of genus Megasphaera downregulated extremely,and Lactobacillus,Succiniclasticum and Faecalibacterium declined significantly.【Conclusion】Newborn piglets oral ingestion of viable probiotic E.faecium has a sustained impact on the composition at the genus or phylum level of colonic microbial community,which is demonstrated by promoting the growth of bacteria beneficial to colon health and simultaneously inhibiting the proliferation of potentially pathogenic bacteria.These findings provide a clear target for future studies on intestinal symbiotic microorganisms modulating intestinal health of piglets.