Gum Arabic (GA) rich dietary fiber it is a water-soluble dietary fiber derived from the dried gummy exudates of the stems and branches of Acacia senegal, GA found to have strong immuno modulator in vitro where it increased IL10 production showing strong anti-inflammatory effects (19).

The aim of this study is to determine the role of gum Arabic in immunomodulation among patients with rheumatoid arthritis.

Butyrate is short chain fatty acids representing the most important end product of colonic bacterial aerobic fermentation of Gum Arabic , it has a potent anti-inflammatory effect and can down regulates TNF a expression by modulating NF-kB-DNA binding activity , in addition butyrate is known to act as histone deacetylase inhibitor in the cells.Recently, in vitro and in vivo data indicates that HDAC inhibitors may have anti-inflammatory effect due to their effects on cell death acting through acetylation of non-histone proteins. The possible anti-rheumatic mechanisms of HDAC inhibitors, including growth arrest in rheumatoid arthritis synovial fibroblasts (RASFs), suppression of pro-inflammatory cytokines, suppressing angiogenesis as well as the protective effects on bone and cartilage against their destruction.

The investigators expect regular intake of GA will raise serum butyrate level. The endogenous butyrate decreases the TNF level. The latter will decrease the number of relapsing episodes, arresting the destruction of joints and improve both survival and life quality of rheumatoid arthritis patients.

Inclusion Criteria:

1. Clinical diagnosis of Rheumatoid Arthritis
2. Clinically stable as evidenced by medical history, complete physical examination
3. All medications and dosages are stable for 6 weeks before study entry,
4. Non Pregnant ladies.

Exclusion Criteria:

• 1- hepatic, cardiovascular, pulmonary, malignant, hematologic, neurologic, infectious, or inflammatory diseases unrelated to Rheumatoid arthritis.

  2-Hospital admission within 4 weeks of start of the study.

  3- Uncontrolled hypertension 4- Asthma or severe atopic disease;