Objective:The causal relationship between eczema and autoimmune diseases has not been previously reported.This study aims to evaluate the causal relationship between eczema and autoimmune diseases. Methods:The two-sample Mendelian randomization(MR)method was used to assess the causal effect of eczema on autoimmune diseases.Summary data from the Genome-Wide Association Study Catalog(GWAS)were obtained from the Integrative Epidemiology Unit(IEU)database.For eczema and autoimmune diseases,genetic instrument variants(GIVs)were identified according to the significant difference(P＜5×10-8).Causal effect estimates were generated using the inverse-variance weighted(IVW)method.MR Egger,maximum likelihood,MR-PRESSO,and MR-RAPS methods were used for alternative analyses.Sensitivity tests,including heterogeneity,horizontal pleiotropy,and leave-one-out analyses,were performed.Finally,reverse causality was assessed. Results:Genetic susceptibility to eczema was associated with an increased risk of Crohn's disease(OR=1.444,95％CI 1.199 to 1.738,P＜0.001)and ulcerative colitis(OR=1.002,95％CI 1.001 to 1.003,P=0.002).However,no causal relationship was found for the other 6 autoimmune diseases,including systemic lupus erythematosus(SLE)(OR=0.932,P=0.401),bullous pemphigoid(BP)(OR=1.191,P=0.642),vitiligo(OR=1.000,P=0.327),multiple sclerosis(MS)(OR=1.000,P=0.965),ankylosing spondylitis(AS)(OR=1.001,P=0.121),rheumatoid arthritis(RA)(OR=1.000,P=0.460).Additionally,no reverse causal relationship was found between autoimmune diseases and eczema. Conclusion:Eczema is associated with an increased risk of Crohn's disease and ulcerative colitis.No causal relationship is found between eczema and SLE,MS,AS,RA,BP,or vitiligo.

Premature ovarian insufficiency (POI) is characterized by the decline or loss of ovarian function before the age of 40 years and account for one major cause of female infertility. Its pathogenesis is complex. Recently, the research on microbiota and reproductive endocrine diseases has become a hot spot. This article reviews the involvement of microbiota in the occurrence and development of POI through immune response, inflammatory factors and metabolic function. At the same time, taking probiotics and fecal microbiota transplantation can correct the dysbiosis of flora, so as to improve the symptoms associated with POI. In the future, it is expected to provide new strategies for the diagnosis and treatment of POI through further research on the relationship between microbiota and POI.

Premature ovarian insufficiency (POI) is characterized by the decline or loss of ovarian function before the age of 40 years and account for one major cause of female infertility. Its pathogenesis is complex. Recently, the research on microbiota and reproductive endocrine diseases has become a hot spot. This article reviews the involvement of microbiota in the occurrence and development of POI through immune response, inflammatory factors and metabolic function. At the same time, taking probiotics and fecal microbiota transplantation can correct the dysbiosis of flora, so as to improve the symptoms associated with POI. In the future, it is expected to provide new strategies for the diagnosis and treatment of POI through further research on the relationship between microbiota and POI.