TNF and rheumatoid arthritis: For example, there is evidence that gut dysbiosis correlates with worse clinical responses to treatment with the most commonly used DMARD, methotrexate.[34,35] Moreover, the treatment of RA with a tumor necrosis factor (TNF)-a inhibitor has been reported to also partially restore the balance within a patient’s gut commensal community, which supports the notion that systemic inflammation in RA may itself be a driver for gut dysbiosis.[36]