Background: Rheumatoid Arthritis (RA) is autoimmune inflammatory disease attacks the synovium of the joints. Both TNFaand interleukin-1 play crucial roles in the pathogenesis of RA. Gum Arabic (GA) is gummy exudates from Acacia Senegal tree. Gum Arabic as a soluble fibre its fermentation by colonic bacteria increases serum butyrate concentrations, so it is considered as prebiotic agent. Gum Arabic (GA) has anti-inflammatory activity through its derivative butyrate. Patients and methods: This is clinical trial phase II in which 40 patients were enrolled aged 18 to 70 years. Patients received 30g/day GA for 12 weeks. TNF α, ESR, and complete blood count were measured and DAS-28 was calculated before and after regular GA consumption. Study approved by the Ethical committee of National Medicines and Poisons Board.Clinical this clinical trial was registered inTrials.gov Identifier: NCT02804581 Registered 19th June 2016. Prospective registration. Results: This study showed significant decrease in level of serum TNF α (p value 0.05) [95% CI, 0.65 -16.5], ESR (p value 0.011) [95% CI, 2.6 -18.89], and number of swollen and tender joints in RA patients after 12 weeks of GA intake which reflected as significant decrease in disease severity score DAS 28 P.V:0.00 [95% CI, 1.25 -1.99]. On the other hand, GA had trivial change in blood indices. Conclusion: Gum Arabic has favorable immune modulator effect on Rheumatoid Arthritis. It can be utilized in clinical practice as adjuvant therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT02804581 Registered 19th June 2016. Prospective registration