Changes in the

Background: Autoimmune diseases have different pathogenic mechanisms but share underlying patterns of gut microbiome perturbation and intestinal barrier dysfunction. Recent evidence suggests that an arthritogenic strain of Objective: To evaluate the changes of Methods: Four databases, including PubMed, Cochrane, Web of Science, and Embase, were searched up to June 17, 2025, to identify studies that detected Study selection: We included articles that addressed both autoimmune diseases without intervention and the detection of Quality assessment: We used the Newcastle-Ottawa Scale (NOS) to independently assess the methodological quality of the case-control studies. The Journal of Biomedical Informatics (JBI) critical appraisal checklists were utilized to assess the quality and risk of bias in cross-sectional studies. Results: Twelve studies were included. These studies were conducted in four different countries and included a total of 1,792 participants (patients with autoimmune disease and healthy controls). Our meta-analysis results indicate that, compared with healthy controls, most patients with autoimmune diseases included in the study had lower levels of Conclusion: The abundance of Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024543767, identifier CRD42024543767.