抗生素使用对冬春季婴幼儿肠道菌群内部相关性的影响

目的 研究抗生素使用对冬春季婴幼儿肠道菌群内部相关性的影响.方法 采用1:1病例对照研究设计,选取于陕西省商洛市中心医院就诊患腹泻疾病的2岁以下患儿为病例组,同期到该医院进行健康体检或免疫接种的健康婴幼儿作为对照组.采用二代测序的技术检测婴幼儿样本粪便中微生物群落的组成结构和多样性.绘制细菌属水平相关性网络图,分析各菌属之间的相关性.结果 本研究共收集粪便样本120例,最终纳入分析的样本数为115.在对照组中,拟杆菌属与其他菌属存在最多关联,大肠埃希菌/志贺菌属、不动杆菌属、芽孢杆菌属和Lysinibacillus菌属存在明显正相关性(r值分别为0.640、0.945、0.892,均P<0.05),后3种菌属数量上的增加直接影响了拟杆菌数量的减少,但拟杆菌却未表现出与大肠埃希菌/志贺菌的负相关性(r=-0.252,P>0.05);在腹泻未使用抗生素组的婴幼儿中,Akkermansia菌与其他菌属存在最多的关联,它与普雷沃氏菌属、Barnesiella菌、地杆菌存在两两正相关性(r值分别为0.735、0.798、0.833,均P<0.05),Akkermansia菌通过与芽孢杆菌和不动杆菌的正相关性(r值分别为0.473、0.401,均P<0.05),影响大肠埃希菌和Lysinibacillus菌属的数量,但Akkermansia菌、芽孢杆菌属却与大肠埃希菌没有直接的相关关系;在腹泻使用抗生素组中,地杆菌属与其他菌属联系最多,并且出现了两大正相关集团,一是以地杆菌为中心,表现为地杆菌与不动杆菌、普雷沃氏菌、Barnesiella菌、Lysinibacillus菌和芽孢杆菌属的正相关关系(r值分别为0.622、0.876、0.911、0.435、0.606,均P<0.05),另一个是以韦荣氏菌为中心,表现为韦荣氏菌与Akkermansia菌、嗜血菌和Megasphaera菌属存在正相关关系(r值分别为0.414、0.773、0.567,均P<0.05),两大集团存在拮抗作用,表现为韦荣氏菌和嗜血菌对地杆菌存在负相关(r=-0.538、-0.380,P<0.05),并且韦荣氏菌丰度的增加会抑制芽孢杆菌、普雷沃氏菌、地杆菌和Barnesiella菌属的丰度值,同时肠球菌丰度的增加也会使第一集团菌属丰度相应减少,双歧杆菌仅对芽孢杆菌存在负相关作用(r=-0.403,P<0.05).抗生素的使用增加了肠道菌群在属水平的内部相关性复杂程度,并改变了与其他菌属联系最多的菌属类别.结论 抗生素的使用导致了婴幼儿肠道菌群微生态失衡.

Effect of antibiotics on internal correlation of intestinal microflora in infants and young children in winter and spring season

Objective To explore the effect of antibiotics on internal correlation of intestinal microflora in infants and young children in winter and spring season.Methods A case-control by 1:1 study design was employed in this research.Infants under 2 years old with diarrhea visiting Shangluo Central Hospital of Shaanxi Province were chosen as case group.At the same period, healthy infants coming to the same hospital for health examination or immunization injection were selected as control group.Structure and diversity of microbial communities in feces of infants and young children were detected by second generation sequencing.Bacteria genus correlation network map was drawn and internal correlations of microflora were analyzed.Results Altogether 120 stool samples were collected in this study and finally 115 samples were included in analysis.In control group, bacteroides were most correlated with other bacteria genus.Escherichia coli/Shigella, Acinetobacter, Bacillus had obvious positive correlation with Lysinibacillus (r value was 0.640, 0.945 and 0.892, respectively, all P<0.05).Quantity increase in latter three bacteria genuses directly caused quantity decrease in bacteroides, but bacteroides did not show negative correlation with Escherichia coli/Shigella (r=-0.252, P>0.05).In infants with diarrhea not treated with antibiotics, Akkermansia had most correlation with other bacteria genuses.It had pairwise positive correlation with Prevotella, Barnesiella and terrabacter (r value was 0.735, 0.798 and 0.833, respectively, all P<0.05).Through positive correlation with bacillus and Acinetobacter (r value was 0.473 and 0.401, respectively, both P<0.05), Akkermansia influenced quantity of Escherichia coli and Lysinibacillus.But Akkermansia and bacillus had no direct correlation with Escherichia coli.In infants with diarrhea treated with antibiotics, terrabacter had most correlation with other bacteria genuses.Two positive correlation groups appeared.One group was centered with terrabacter, showing positive correlation of terrabacter with Acinetobacter, Prevotella, Barnesiella, Lysinibacillus and Bacillus (r value was 0.622, 0.876, 0.911, 0.435 and 0.606, respectively, all P<0.05).The other group was centered with Veillonella, showing positive correlation of Veillonella with Akkermansia, hemophilus and Megasphaera (r value was 0.414, 0.773 and 0.567, respectively, all P<0.05).There was antagonistic effect between two groups, representing by negative correlation of Veillonella andhemophilus with terrabacter (r value was-0.538 and-0.380, respectively, both P<0.05).Abundance increase in Veillonella inhibited abundance of bacillus, Prevotella, terrabacter and Barnesiella.Meanwhile, abundance increase in enterococcus could cause abundance decrease in first group bacteria genuses.Bacillus bifidus only had negative correlation with bacillus (r=-0.403, P<0.05).Antibiotics usage increased the complexity of internal correlations of intestinal flora at genus level and altered bacteria genus which had most internal correlations with other bacteria.Conclusion Antibiotics usage induces dysbiosis of intestinal microflora communities in infants and young children.