Changes In Intestinal Flora During Feeding Intolerance In Premature Infants

Objective: to study the changes and diversity of intestinal microflora of premature infants with intolerance and tolerance during breastmilk feeding or formula milk feeding.Methods: This was a prospective observational study.A total of 24 premature infants admitted to the Department of Neonatology,Changsha Central Hospital from December,2018 to March,2019 were enrolled.The cases divided into four groups: breastfeeding-tolerant group(A group),breastfeeding-intolerant group(B group),formula milk feeding tolerant group(C group),and formula milk feeding intolerant group(D group)in the manner of feeding and tolerant.6 cases were enrolled in each group.Clinical data of all infants were collected.The fresh stool specimen of infants were collected in 7 days after birth,and all specimens were stored in-20? freezer,subsequently investigated by 16 s RNA high-throughput sequencing.The results were filtered by paired end reads software based on RNA overlapping-splicing and tags calculation.Operational taxonomic units(OTU)were analyzed for intestinal microbiome richness.Intestinal microbiome diversity was measured with Shannon Index,Chao1 Index,ACE Index,and Metastats software was used to compare the taxonomic differences among different groups.Results: There were on significant differences among four groups in terms of mean birth weight and mean gestational age(P> 0.05).There were not significant difference among four groups in terms of Chao1 Index,ACE Index,and Shannon Index(P> 0.05),but it was found that the diversity in D group was highest,followed by B group,A group,and C group.Metastats analysis showed that there were significant differences between the D group and B group at the generic level of paraffin bacteria,proteobacter,erwinia and roche bacteria(P<0.05).Among them,the sample abundance of edible alkanes in D group was higher than that in B group.The abundance of e.coli,proteobacter and roche's bacteria in the B group was higher than that in D group.There was a significant difference in the level of actinomycetes between B group and D group(P<0.05),and the actinomycetes abundance in B group was higher than that in D group.There were significant differences in the generic levels between B group and D group(P<0.05).There were significant differences between C group and D group in the genera of purple bacillus,salmonella and streptococcus.The abundance of purple bacillus and salmonella in the D group was higher than that C group(P<0.05).The abundance of streptococcus in C group was higher than that D group.The proteobacteria abundance in the formula feeding intolerance group was higher than that in the formula feeding tolerance group(P<0.05).Conclusions The diversity and abundant of intestinal flora is associated with feeding pattern and tolerant condition.