Changes in the Subdoligranulum genus in patients with autoimmune disease: A systematic review and meta-analysis

露 申^1,2Bo Shen^1,2*Chia-Hsien Hsu^1,2*

• ¹Department of Clinical Laboratory, Taizhou Hospital, Wenzhou Medical University, Linhai, China
• ²Zhejiang Taizhou Hospital, Taizhou, Zhejiang Province, China

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 Subdoligranulum causes a local inflammatory response in the gut. Therefore, the aim of this review is to systemically summarize the relationships between Subdoligranulum and multiple autoimmune diseases.Objective: To evaluate the changes of Subdoligranulum in different autoimmune diseases. Methods: Four databases, including PubMed, Cochrane, Web of Science, and Embase, were searched up to June 17, 2025, to identify studies that detected Subdoligranulum in autoimmune diseases. We conducted a meta-analysis to compare the differences in Subdoligranulum between healthy people and patients with autoimmune diseases and compared the changes in these bacteria under different treatments for similar diseases or the same disease. The relationships between Subdoligranulum and inflammation-related biomarkers were also analysed.Study selection: We included articles that addressed both autoimmune diseases without intervention and the detection of Subdoligranulum in faeces, and presented a description of changes in bacteria in patients and healthy controls.Quality assessment: We used the Newcastle-Ottawa Scale (NOS) to independently assess the methodological quality of the case-control studies. The 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 4 different countries and included a total of 1792 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 Subdoligranulum (P=0.027). In addition, we also found that bacteria were associated with several inflammation-related biomarkers. For example, bacterial levels were positively correlated with C-reactive protein (CRP), LPS-binding protein (LBP) and Treg cells. However, the levels were negatively correlated with IL-8. These relationships may underly both the occurrence and development of autoimmune diseases.The abundance of Subdoligranulum in patients with organ-specific autoimmune diseases is decreased, whereas no consistent findings were observed for systemic autoimmune diseases.Registration number: PROSPERO database (registry number: CRD42024543767).