Analysis Of The Diversity Of Intestinal Flora In Infants With Cow’s Milk Protein Allergy By Different Feeding Methods

Objective:The structure and diversity of intestinal flora in infants with cow’s milk protein allergy(CMPA)in different feeding methods were analyzed to provide an in-depth understanding of the pathogenesis of intestinal flora in CMPA and to provide a scientific basis for the rational selection of probiotic preparations to assist in the treatment of children with CMPA.Methods:24 feces of infants with CMPA were collected for the CMPA group,which was divided into the breast-fed CMPA group(BC),mixed-fed CMPA group(MC),and formula-fed CMPA group(FC)according to the different feeding methods,and the stools of 26 healthy infants as the Normal group,similarly,depending on the feeding method,they were divided into breast-fed Normal group(BN),mixed-fed Normal group(MN),and formula-fed Normal group(FN).Stools were collected,bacterial DNA was extracted,and the 16 S r DNA V3-V5 region was sequenced in high throughput to analyze the differences in the structure and diversity of the intestinal flora of infants with CMPA by different feeding methods from four aspects: ANOSIM analysis,diversity index,community composition analysis,and comparative species analysis.Results:1.The diversity of intestinal flora was higher in the CMPA group than in the Normal group,which the difference was significant(P <0.05).At the phylum level,the CMPA group had higher percentages of the abundance of Firmicutes and Proteobacteria and lower percentages of Actinobacteria phylum than the Normal group,and both differences were significant(P <0.05).At the genus level,compared with the Normal group,the percentage of the abundance of Streptococcus,unclassified＿f＿＿Enterobacteriacea,Citrobacter,Clostridium＿sensu＿stricto＿1,and Staphylococcus in the CMPA group was higher,while bifidobacterium ran to a lower level,with statistically significant differences(P <0.05).2.The diversity of intestinal flora was higher in the BC group than in the BN group,and the difference was statistically significant(P < 0.05).At the phylum level,the percentage of the abundance of Proteobacteria was higher in the BC group compared with the BN group,while Actinobacteria was lower,which was significant(P <0.05).At the genus level,the percentage of the abundance of unclassified＿f＿＿Enterobacteriaceae,Citrobacter,and Erysipelatoclostridium was higher in the BC group and lower in Bifidobacteria than in the BN group,which the differences were statistically significant(P< 0.05),and Clostridium was not detected in the BN Group.3.There was no significant difference in intestinal flora diversity between the MC group and the MN group(P >0.05).At the phylum level,compared with the MN group,the percentage of the abundance of Firmicutes in the MC group was higher,while Actinobacteriota and Bacteroidota were lower,statistically significant(P <0.05).At the genus level,compared with the MN group,the percentage of the abundance of Streptococcus and Rothia in the MC group was higher,while Bifidobacterium,Blautia,and Bacteroides ran to lower abundance,statistically significant(P <0.05).4.There was no difference in intestinal flora diversity between FC and FN groups(P >0.05).At the phylum level,compared with the FN group,the percentage of the abundance of Proteobacteria in the FC group was higher,while Actinobacteriota was lower,which was statistically significant(P <0.05).At the genus level,compared with the FN group,the percentage of the abundance of unclassified＿f＿＿Enterobacteriaceae,Citrobacter,and Streptococcus was higher in the FC group,but while bifidobacteria and Collinsella ran to lower abundance,with statistical significance(P <0.05),and Collinsella was’ not detected in the FC group.Conclusion:1.The intestinal flora diversity of infants with CMPA,although richer,does not indicate that it is beneficial.Among them,increases in Streptococcus,unclassified＿f＿＿Enterobacteriaceae,Citrobacter,Clostridium＿sensu＿stricto＿1,and Staphylococcus and decreases in bifidobacterium were strongly associated with the occurrence of CMPA.2.Changes in intestinal flora in infants with CMPA occurring in different feeding patterns were not completely consistent.Increases in unclassified＿f＿＿Enterobacteriaceae,Citrobacter,Erysipelatoclostridium were closely associated with breast-fed CMPA,increases in Streptococcus and Rothia were closely associated with mixed-fed CMPA and increases in unclassified＿f＿＿Enterobacteriaceae,Citrobacter and Streptococcus increases were strongly associated with formula-fed CMPA.3.Unclassified＿f＿＿Enterobacteriaceae,Streptococcus,Bifidobacterium and Citrobacter are the main taxa responsible for the differences in the intestinal flora of infants with CMPA by different feeding methods,and different probiotic preparations need to be selected according to feeding methods.