Dynamic Changes Of Gut Microbiota And SIgA In Preterm Infants With Feeding Intolerance

Objective:By detecting the intestinal flora and sIgA of feeding intolerance（FI）premature infants during the intolerance phase and symptom remission phase,we can understand the abundance diversity of intestinal flora and the changes of intestinal local immunity of the sick premature infants,and explore the intestinal flora The intrinsic correlation between sIgA and premature infant disease provides a theoretical basis for probiotics treatment of FI.It provides a new way for the early prevention and treatment of FI.Methods:Late preterm infants with gestational age >34 weeks admitted to the Neonatal Department of the Second Hospital of Jilin University from December 2020 to December 2021 were selected as experimental subjects.Those who met the inclusion and exclusion criteria of feeding intolerance were included in the experimental group.Stool samples of preterm infants in the experimental group when feeding intolerance symptoms occurred were collected and recorded as intolerance in the experimental group（GE7）.Feces samples of the preterm infants in the experimental group were collected when their symptoms basically disappeared after treatment,and recorded as after remission in the experimental group（GE14）.Samples from the subjects who met the inclusion and exclusion criteria of the control group were collected at 5-7 days,10-14 days and recorded as control group 1（GC7）and control group 2（GC14）.In this study,a total of 31 preterm infants were included in the experimental group,and 62 specimens were included in the experimental group.There were 31 premature infants and 62 specimens in the control group.The general data were statistically analyzed,and the fecal samples were determined by 16 Sr DNA high-throughput sequencing ELISA method,and the intestinal flora characteristics and sIgA content of the preterm infants in the experimental group and control group were analyzed.Results:1.The number of OTUs in the experimental group was significantly lower than that in the control group 1（GC7）.With the remission of symptoms of preterm infants in the experimental group,the number of OTUs in the experimental group（GC14）increased significantly,but was still lower than that in the control group 2（GC14）.2.The Observed species index and Chao1 Index in the experimental group were significantly lower than those in the control group.With the remission of the symptoms of intolerance,the abundance of intestinal flora increased gradually,there was no difference in species richness between the remission group and the control group,and the Simpson Index of the intolerance period in the experimental group was significantly lower than that in the remission group（p <0.05）.3.The main species of the four groups were the same,but the relative abundance of the different groups was different at different levels of phylum,class,order,family and genus.4.The results of Lefse analysis showed that the relative abundance of the control group was higher than that of the test group,and the relative content of the control group was higher than that of the test group The relative abundance of Klebsiella（Enterobacteriaceae,Proteobacterium）,pantoea（Owen,Proteobacterium）,Enterococcus（enterococcus,Lactobacillus,bacillus,pachyderm）and clostridium Bacillus（Clostridium,pachyderm）in the experimental group were significantly higher than those in the control group.5.The control group 14 days and the experimental group after remission specimens were detected higher levels of Pseudomonas.6.The results showed that the fecal SIGA content in preterm infants increased with the increase of age,and the SIGA content in experimental group was lower than that in control group（p < 0.05）,with the remission of intolerance symptoms,SIGA content increased gradually and there was no significant difference compared with control group 2.7.SIGA was positively correlated with Klebsiella and pantoea in the feeding intolerance group.Conclusions:1.The OTUs and α diversity of intestinal microflora in feeding intolerance children were significantly decreased,and the symptoms of feeding intolerance were alleviated.2.There were significant differences in intestinal flora between FI group and control group.The opportunistic pathogens such as pantoea,Bacillus and Klebsiella increased and the number of Rotenella decreased compared with control group.3.The content of SIGA increased with the age of birth,decreased with feeding intolerance period and increased with symptom relief.