| Objective:16S DNA high-throughput sequencing technology was used to compare the characteristics and differences of intestinal flora between preterm and normal preterm infants with brain injury,so as to further explore the potential relationship between intestinal flora and brain injury in preterm infants,and provide new ideas for prevention and treatment of brain injury in preterm infants.Methods:In 21 cases diagnosed brain injury of premature infants as brain injury group and control group for the same period according to the hospital,random length of stay in the hospital of 17 cases of normal preterm infants,the first day of the two groups respectively after birth,the third day and on the seventh day to collect stool samples,with a high molecular weight sequencing platform of fecal samples of 16s RNA amplification,V3,V4 area are using high-throughput sequencing machine after Miseq for sequencing,through data processing and analysis of biology,comparison between groups of the composition and diversity of intestinal flora.Results:①A total of 114 fecal samples of premature infants were sent for examination,among which 33 failed to achieve PCR amplification.All were feces samples obtained from the first day after the birth of premature infants.81 samples were successfully sequentially,and a total of 1609 OTUs were obtained.②species composition analysis:At the level of phylum,Firmicutes、Proteobacteria and Actinobacteria are the dominant bacteria in the brain injury group and control group on the third and seventh day after birth.On the third day after birth,the relative abundance of Actinobacteria was significantly increased in the control group(P<0.05),and the relative abundance of the remaining dominant bacteria was significantly increased in the brain injury group(P<0.05).On the seventh day after birth,the relative abundance of Actinobacteria was significantly increasedd in the control group(P<0.05),and the relative abundance of the remaining dominant bacteria were no statistically significant difference between the two groups.On the level of genera,Enterococcus was the dominant bacteria in the brain injury group and control group on the third day after birth and the seventh day after birth.On the third day after birth,the relative abundance of Enterococcus in the brain injury group increased(P<0.05),the relative abundance of Bifidobacterium and Rothia increased in the control group(P<0.05),On the seventh day after birth,the relative abundance of Staphylococcuss in the brain injury group increased(P<0.05),the relative abundance of Bifidobacterium in the control group increased(P<0.05).LEfSe analysis:Analysis of all samples of the brain injury group and the control group on the third and seventh days revealed that the brain injury group took Lactobacillales as the main characteristic difference of bacteria.In the control group,Bifidobacterium was the main characteristic differential bacteria.On the third day after birth,the brain injury group took Enterococcus as the main characteristic differential bacteria,while the control group took Rothia as the main characteristic differential bacteria.On the seventh day after birth,there were no significant differences between the two groups.③Species diversity analysis:Alpha diversity analysis:On the third day,Shannon index:brain injury group<control group(P<0.05),Simpson index:brain injury group<control group(P<0.05).Conclusion:1.At the phylum level,Firmicutes、Proteobacteria and Actinobacteria are the dominant phylum,while at the genus level,Enterococcus is the dominant genus at week after birth.2.Brain damage in preterm infants may be associated with abnormal colonization of intestinal flora in early stage,which is manifested by decreased intestinal flora diversity.At the phylum level,the abundance of Actinobacteria decreased,while the abundance of Firmicutes and Proteobacteria increased in the intestinal flora composition of preterm infants with brain injury.At the genus level,the abundance of Bifidobacterium and Rothia decreased,while the abundance of Enterococcus and Staphylococcuss increased.The changes on the third day after birth were more obvious than on the seventh day. |
