THERAPEUTIC EFFECT OF A SYNBIOTIC ON INFLAMMATORY SIGNALING AND GUT MICROBIOME MODULATION IN COLLAGEN-INDUCED ARTHRITIC C57BL/6 MICE

Yara A. Nader, A. Helen*

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic joint inflammation and gut microbiota dysbiosis. Modulating the gut microbiome may be a promising adjunctive strategy for RA management. This study evaluated the effects of combined probiotic and prebiotic (fructooligosaccharides, FOS) supplementation on inflammatory pathways and gut microbial composition in collagen-induced arthritic (CIA) C57BL/6 mice. Arthritis was induced using type II collagen with complete Freund’s adjuvant (CFA). Mice were divided into three groups: control, disease, and Synbiotic-treated groups. The treated group received oral Synbiotics at fixed daily doses for 28 days. Inflammatory markers and signaling pathways were assessed. Colon histology was examined, and gut microbial diversity was evaluated using 16S rRNA gene sequencing. Treated mice exhibited reduced TLR2 expression decreased by approximately 10.2% compared with the disease group and decreased nuclear translocation of NF-κB (p < 0.05), decreased Level of TNF-α and increased level of IL-10 (p < 0.05). Microbiome analysis revealed descriptive compositional shifts, including increased relative abundance of Lactobacillus and partial normalization of the Firmicutes/Bacteroidetes ratio. Histological evaluation demonstrated improved colonic mucosal architecture in treated mice. In aggregate, these findings support the potential of synbiotic administration as a complementary strategy for modulating gut-immune interactions in RA, warranting further investigation in larger, controlled studies.