Abstract:
Familial Mediterranean Fever (FMF) is a hereditary auto-inflammatory disease endemic to the Middle East and Mediterranean populations. Despite advances in understanding its genetic basis, FMF pathophysiology remains incompletely understood. Emerging evidence suggests the gut microbiota plays a critical role in regulating inflammation and immune responses, raising the possibility that microbiome alterations may contribute to FMF severity. However, research in the Arab region, particularly in Lebanon, remains limited.
This study investigated the gut microbiota composition of 16 FMF patients and 13 healthy controls in Lebanon using 16S rRNA gene sequencing. Clinical data were collected, and disease severity was scored using the International Severity Scoring System for FMF (ISSF). Alpha and beta diversity analyses, as well as differential abundance testing, were conducted to explore microbial differences between groups. Our findings revealed no significant differences in gut microbiota composition or diversity between FMF patients and healthy controls, nor among FMF subgroups stratified by disease severity. Minor compositional variations were observed, such as increased abundance of Synergistota in FMF patients; however, none reached statistical significance. These results contrast with previous studies reporting inflammatory dysbiosis and reduced microbial diversity in FMF cohorts. Multiple factors may account for these discrepancies, including small sample size, moderate sequencing quality, remission status, colchicine treatment, and the difficulty of recruiting both FMF patients and healthy volunteers.
The absence of significant microbial shifts reflects the complexity of host–microbiota interactions in FMF. Future studies should aim to include larger and more diverse cohorts, apply higher-resolution sequencing, and incorporate functional microbiome profiling to better understand the role of the gut microbiota in FMF pathogenesis and progression.
