The Study On The Correlation Between Skin Microbe And Moderate And Severe Psoriasis Vulgaris

Background and purposePsoriasis is a chronic inflammatory disease that can affect multiple systems throughout the body and seriously affect the quality of life of patients.The pathological features of psoriasis are excessive proliferation of keratinocytes and infiltration of inflammatory cells.The exact mechanism of psoriasis is not clear,and activation of T cells was believed to play an essential role in the pathogenesis of psoriasis.In recent years,the role of skin microbiome in the pathogenesis of psoriasis has been widely concerned.Differences in microbiome between psoriasis patients and healthy skin were found.At the same time,skin microbiome are also associated with several immune-mediated diseases,such as atopic dermatitis vitiligo and suppurative sweat adenitis.However,there is still a lack of standardized experimental methods in these studies,resulting in differences and even contradictory results.Therefore,this study will further clear skin microbiome in psoriasis lesion skin and healthy skin composition and the distribution characteristics and find the relationship between skin microbial diversity and psoriasis lesions area and severity index(PASI score)and species with significant differences.To explore the role of skin microbiome in the pathogenesis of psoriasis and provide new ideas for clinical treatment.MethodsThe clinical samples were collected by skin swabs and sampled in different areas(greasy area and dry area).After total microbiome DNA extraction and PCR amplification,16 S rDNA V3-V4 variable region was used for sequencing.OTU(Operational Taxonomic Units)were constructed from sequencing data based on the concept of ASVs(Amplicon Sequence Variants),which is equivalent to clustering with 100% similarity.ASV characteristic sequences and ASV abundance tables were obtained for species annotation and species composition analysis.Skin microbiota diversity analysis was conducted to find differences in skin microbiota diversity within and between groups,including Alpha diversity analysis,species diversity curves and Beta diversity analysis.Spearman analysis was used to analyze the relationship between the microbial diversity index of psoriasis lesion skin group and PASI score.LEf Se(LDA Effect Size)analysis was used to find the species with remarkable differences in abundance between groups,that is,biomarkers.Finally,PICRUSt2(genetic Investigation of Communities by Reconstruction of Unobserved States)was used to predict the function of the flora.Results1.The composition of dominant species in each group was similar at different classification levels,but the relative abundance of some dominant species,such as Actinobacteriota,Bacteroidota,Staphylococcus and Cutibacterium,gradually changed from healthy skin to psoriatic non-lesions skin and then to lesions skin.2.Under different disease states(psoriasis non-lesion skin,psoriasis lesion skin and healthy skin),the richness and evenness of skin microbiota in dry area were higher than that in greasy area.The diversity of skin microbiota in patients with psoriasis decreased and the non-lesion skin microbiota of psoriasis was in a transitional state between the two groups.Spearman analysis showed that the diversity index of psoriasis lesions group was unrelated to PASI score and all P values were greater than 0.05.3.The microflora composition of psoriasis lesions group and healthy control group was significantly different,Pr=0.00(P<0.05,the difference was statistically significant).4.The differential species of skin microbiota in lesion skin of patients with psoriasis were Chryseobacterium and Enhydrobacter at the genus level,and Chryseobacterium＿unclassified and Enhydrobacter＿unclassifiedthe at species level.The differential species of skin microbiota in healthy control group were Cutibacterium,Serratia and Paraburkholderia at the genus level,and Cutibacterium＿unclassified,uncultured＿Serratia＿sp and Paraburkholderia＿unclassified at species level.5.PICRUSt2 function prediction showed that L-tryptophan and L-methionine biosynthesis increased and L-isoleucine biosynthesis decreased in psoriasis lesions compared with healthy controls.Conclusions1.The composition of dominant species of skin microbiota in psoriasis lesion skin group,psoriasis non-lesion skin group and healthy skin group was similar,but the relative abundance of each dominant species was different.2.The diversity of skin microbiota in patients with psoriasis decreased and was not related to PASI score,and the non-lesions skin microbiota in psoriasis was in a transitional state between the two groups.3.The microflora composition of psoriasis lesions group and healthy control group was significantly different.4.The differential species of skin microbiota in lesion skin of patients with psoriasis were significantly different from those in healthy controls.The differential species of skin microbiota in lesion skin of patients with psoriasis were Chryseobacterium and Enhydrobacter.The differential species of skin microbiota in healthy control group were Cutibacterium,Serratia and Paraburkholderia.