The Research Of Relationship Between Seasonal Allergic Rhinitis And Intestinal Flora

Objective:To discover the intestinal flora characteristics of patients with seasonal allergic rhinitis,and to provide a more adequate theoretical basis for the treatment of seasonal allergic rhinitis by probiotics.Methods:Forty-nine patients with seasonal allergic rhinitis who attended the outpatient clinic of the Department of Rhinolaryngology、Head and Neck Surgery at the Affiliated Hospital of Yan’an University from August to October 2022 have been selected,and thirty-four healthy patients who underwent physicl examination in the hospital during the same period were selected.General clinical data and stool samples were collected from all enrolled subjects.The genomic DNA of the stool samples was extracted,the 16SrDNA gene V3-V4 high-variable region was sequenced,and the biological information was analyzed to analyze the characteristics of intestinal flora in seasonal allergic rhinitis and healthy individuals.Results:Analysis of the intestinal flora:The results of the community structure analysis showed that Bacteroides,Faecalibacterium,Escherichia-Shigella and Prevotella were the major dominant bacteria at the genus level in the SAR and healthy groups,and the total percentage of these four dominant bacteria at the genus level was more than 58%of the total bacteria,and Bacteroides and Faecalibacterium were relatively dominant.The Firmicutes,the Bacteroidota,the Proteobacteria and the Actinobacteriota were the major dominant bacteria at the phylum level in the SAR and healthy groups.The total percentage of these four dominant bacteria at the phylum level was more than 99%of the total bacteria,and Firmicutes and Bacteroidota were relatively dominant.The dilution curves showed that the amount of sequencing data of the samples in this study was sufficient.there were no significant difference between SAR and healthy groups in alpha diversity related indices chao1 index,observed species index,and shannon index(P>0.05).The results of Rank Abundance analysis showed that the species composition of the SAR group was richer than that of the healthy group;there was no significant difference in the uniformity of species composition between the two groups.beta diversity PCoA analysis suggested that there were differences in the bacterial community Structure between the SAR group and the healthy group(P<0.05),and there were some differences in the colony composition between the two groups,but the differentiation was not obvious.LEfSe analysis showed that:Turicibacter,Campylobacteria,Campilobacterota,Campylobacterales and Parasutterella were relatively more abundant in the SAR group and less abundant in the healthy group;Romboutsia,Peptostreptococcaceae,Eubacterium_hallii_group,Lactobacillaceae,Lactobacillus,Haemophilus,Pasteurellaceae,Pasteurellales,Streptococcaceae,Moraxella,Neisseria,NeisseriaceaeRuminococcus_gauvreauii_group were relatively more abundant in the healthy group and relatively less abundant in the SAR group.Conclusions:The species composition of SAR group was richer than that ofhealthy group and the flora structure of the two groups was different.the relative abundance of Lactobacillus,Eubacterium_hallii_group,and Ruminococcus_gauvreauii_group was low in SAR patients;Campylobacter and Parasutterella had ahigh relative abundance.The imbalance of intestinal flora may be related to theoccurrence and development of SAR.