| Objective:Necrotizing enterocolitis（NEC）is the most common disease affecting the intestinal tract of premature infants,which is common in premature infants and has a high fatality rate of about 20-30%.Children with NEC who survive also have many long-term complications such as broken-bowel syndrome,parenteral nutrition-related cholestasis and liver dysfunction,malnutrition,and metabolic bone disease.The pathogenesis of NEC is still not fully understood.The purpose of this study was to understand the changes of intestinal flora in neonates with necrotizing enterocolitis by high-throughput sequencing,and to provide theoretical basis for diagnosis and treatment of NEC.Methods:Premature infants hospitalized in Children’s Hospital of Anhui Medical University from January 2020 to July 2021 were divided into two groups: the non-NEC group（control group）and the NEC group（experimental group）.The latter group was divided into two subgroups according to the treatment before and after treatment: the NEC group（before treatment）and the NEC group（after treatment）.Stool samples were collected within 24 hours after diagnosis of NEC in the experimental group（before treatment）and in the control group（after treatment）when clinical symptoms improved significantly and full feeding was achieved.High-throughput sequencing technology was used to conduct gene sequencing on children’s fecal to analyze the diversity of fecal samples and identify bacterial species.Results:A total of 66 stool samples were collected,including 44 in the experimental group and 22 in the control group.In the experimental group,the average gestational age at birth was（35±2）w,the cesarean section rate was 41%（9/22）,breast-feeding rate was 36%（8/22）,male 45%（10/22）,female 56%（12/22）,and birth weight was（2274±236）g.In the control group,the average gestational age at birth was（35±3）w,cesarean section rate was 41%（9/22）,breast-feeding rate was 36%（8/22）,male 45%（10/22）,female 56%（12/22）,and birth weight was（2358±227）g.The diversity index of intestinal flora in experimental group（before treatment）and control group was0.93±0.50 and 1.10±0.34,respectively.Sobs indices were 19.36±7.08 and 21.96±4.76,respectively.Simpson index were 0.51±0.26 and 0.46±0.16,respectively.Chao values were 22.16±7.62 and 25.44±6.97,respectively.There was no statistical difference in the richness and evenness of intestinal flora between the experimental group（before treatment）and the control group（P＆GT;0.05）.The diversity index of intestinal flora in experimental group before and after treatment was 0.93±0.50 and 0.91±0.51,respectively.Sobs indices were 19.36±7.08 and 21.23±6.43,respectively.Simpson index were 0.51±0.26 and 0.58±0.25,respectively.Chao values were 22.16±7.62 and24.25±7.10,respectively.There was no statistical difference in the richness and evenness of intestinal flora in the experimental group before and after treatment（P＆GT;0.05）There were significant differences in the composition of intestinal flora between the experimental group（before treatment）and the control group: Enterococcus（40%）,Firmicutes（21%）,Proteobacteria（23%）and bifidobacteria（10%）dominated the experimental group;The control group was dominated by Escherichia coli（42%）,enterococcus（25%）,bifidobacteria（30%）and Firmicutes（2%）.There were significant differences in the composition of intestinal flora before and after treatment in the experimental group: Enterococcus（40%）,Firmicutes（21%）,proteobacteria（23%）and bifidobacteria（10%）were the main groups in the experimental group（before treatment）.The experimental group（after treatment）was dominated by Escherichia coli（28%）,Enterococcus（21%）,bifidobacteria（28%）,Firmicutes（8%）and Proteobacteria（about 5%）.There was no significant difference in the proportion of Klebsiella between the two groups.Conclusion: The results of this study showed that the intestinal flora of the experimental group（before treatment）and the control group,as well as the experimental group before and after treatment were significantly different,indicating that the abundance of firmicutes and proteobacteria in the intestinal flora of NEC children increased,and the abundance of bifidobacteria decreased. |
