Inclusion Criteria:  New diagnosis of rheumatoid arthritis (RA) (<6 months) meeting 2010 ACR/EULAR for RA Scheduled to begin treatment with methotrexate at any dose as standard medical care Able and willing to provide written informed consent prior to any study specific procedures Age 18 years and above at time of enrollment Subjects not excluded based on race or ethnicity  Exclusion Criteria:  Participants who are pregnant or are currently breastfeeding History of sensitivity to study compound or any of their excipients Previous intolerance to SCFA or related compounds Current (within 3 months of screening) treatment with csDMARDs Current or past (ever) treatment with biologic therapies (including but not limited to anti-TNF, anti-IL-17, anti-IL-12/23) Current antibiotic treatment (within 3 months of screening) Current consumption of probiotics (within 3 months of screening) Severe hepatic impairment (eg, ascites and/or clinical signs of coagulopathy) Renal failure (eGFR <30 or requiring dialysis) by history History of other autoimmune disease Current immunodeficiency state (e.g., cancer, HIV, others)