Rheumatoid arthritis (RA) remains in the great majority of individuals a disease that is difficult and costly to treat, and results in substantial personal and societal costs [1]. Because of this, there are many efforts underway to develop prevention strategies applicable to the pre-RA phase, a period in which individuals who ultimately develop seropositive disease exhibit predictive RA-related autoantibodies in serum but lack full manifestations of clinical, or classified, RA [2]. All of the prevention trials to date have utilized drugs that are commonly used and/or approved to treat patients with clinical RA; however, there is an increasing understanding that there are very likely different immune processes underway during the early pre-RA period, which may extend for up to 15–20 years prior to onset of clinical signs and symptoms [3]. Key immune processes in the pre-RA phase likely involve mucosal inflammation and dysbiosis that drive the loss of tolerance to self-antigens [4]