The Effects On The Gut Microbiome Of Infants Delivered Before Term By Cesarean Section Of Probiotics And Antibiotic Using 16s RRNA Quantitative Polymerase Chain Reaction Sequencing

Background The establishment of intestinal flora in early life can influence the long-term life activities of individuals.Compared with full-term infants,the intestinal microflora of premature infants is established significantly later,the abundance and diversity of microflora are lower,and the types and contents of pathogenic bacteria are in higher numbers.This discrepancy might be because preterm infants are frequently exposed to a variety of medical factors.Delivery mode and antibiotics are the most common of these therapeutic factors.Cesarean section disrupt the mother-to-neonate transmission of microbiota and decreases the abundance of bifidobacteria in the early gut microbiota of infants.Antibiotic applications have significant effects on the evolution of the infant gut flora in early life.Therefore,the gut flora of premature infants delivered by cesarean section is more prone to disorders,which affects the development of substance metabolites and the immune system causing further diseases.Probiotic interventions early in life may help to improve intestinal flora disorders,but previous studies did not deeply explore the effects of probiotics supplementation in early life.Objective This study aimed to investigate the effects on the gut microbiome of infants delivered before term by cesarean section to compare probiotics with antibiotic by 16 S rRNA quantitative polymerase chain reaction(qPCR)sequencing.Methods 40 premature infants with cesarean section were divided into four groups according to exposure to antibiotics or probiotics,namely,the N group(No-probiotics and No-antibiotics),A group(antibiotics),P group(probiotics)and the AP group(antibiotics+probiotics).Fecal samples were collected on day 1,3 and10.And the microflora data detected by 16 S rRNA qPCR sequencing technology.Then the Bugbase tool was used to phenotype prediction,the Tax4 Fun tool was used to function prediction,and the i Path software was used to predict the metabolic pathways of intestinal bacteria.Results The gut microbiota of all of the premature infants with cesarean delivery was mainly composed of Proteobacteria,Firmicutes,Bacteroidetes,and Actinobacteria.And at the phylum level,the gut microbiota of the four groups of premature infants showed a trend of decreasing proteobacteria and increasing firmicutes with the time of day 1,3,and 10.And the four groups of premature infants also showed a gradual decrease in the abundance of aerobic bacteria and a gradual increase in the abundance of anaerobic bacteria with the time of day 1,3,and 10.Compared with the N-day10 group,in the A-day10 group the abundance of unidentified enterobacteriaceae and Parabacteroides was higher,whereas that of Bifidobacterium was lower.In addition,in the A-day10 group the replication and repair(P = 0.049)and nucleotide metabolism(P = 0.047)were significantly lower,and the purine metabolism pathways was also significantly lower(P < 0.05).Compared with N-day10 group,in the P-day10 group the Bifidobacterium,Lactobacillus and Streptococcus were more abundant,and the cellular community prokaryote function was also significantly higher(P = 0.042).Compared with the A-day10 group,the AP-day10 group had fewer Clostridium difficile,and the replication and repair(P = 0.01)and nucleotide metabolism(P = 0.001)were significantly higher.Conclusion The gut microbiota of premature infants born by cesarean section was mainly composed of four significant phyla,and the variational tendency from proteobacteria to firmicutes and the transformation from aerobic bacteria to anaerobic bacteria was observed at 1,3,and 10 days.Antibiotics is damaging to the composition,function and metabolic pathways of intestinal flora in premature infants with cesarean section.And probiotics not only favors the composition and function of intestinal flora but also alleviate the damage of antibiotics to the composition and function intestinal flora,which supports that restoration of the normal gut microbiota of premature infants delivered by cesarean section with antibiotic treatment may be achieved with probiotics.