FUSOBACTERIUM AS A POTENTIAL PATHOGENETIC FACTOR IN ENDOMETRIOSIS: CURRENT EVIDENCE, METHODOLOGICAL CHALLENGES, AND CLINICAL IMPLICATIONS

Background: Endometriosis is a chronic inflammatory gynecological disorder with an incompletely understood etiology. While hormonal, immunological, and genetic factors have been extensively studied, increasing attention has recently been directed toward the potential role of microbial agents in disease pathogenesis. Among these, Fusobacterium, particularly Fusobacterium nucleatum, has emerged as a candidate pathogen based on translational and experimental findings. Objective: This narrative review aims to critically evaluate current evidence regarding the association between Fusobacterium and endometriosis, assess the biological plausibility of a pathogenic role, and identify methodological limitations and clinical implications. Methods: A structured literature search was conducted in PubMed for publications addressing Fusobacterium in the context of endometriosis, including human studies, experimental models, and relevant commentaries. Evidence was synthesized thematically, with emphasis on study design, detection methods, and consistency of findings. Results: Available data suggest that Fusobacterium may be present in endometrial tissues of some women with endometriosis and may promote inflammatory signaling and lesion development in experimental models. However, recent human studies have reported conflicting results, including a lack of significant Fusobacterium enrichment in eutopic endometrium. These discrepancies appear to be influenced by differences in patient selection, sampling strategies, low-biomass contamination risk, and microbiological detection techniques. Conclusion: Although Fusobacterium represents a biologically plausible contributor to endometriosis pathophysiology, current evidence remains inconclusive. Further standardized, well-controlled studies are required before diagnostic or therapeutic strategies targeting this bacterium can be considered in clinical practice.