We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of “coherence,” that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.Impact statementRheumatoid arthritis (RA) is accompanied by long-term inflammation that is mediated by cytokines and cross-reactive (auto-)antigens. Here we suggest one explanation is the presence of a (dormant) microbiome in RA that sheds the highly potent inflammagen, lipopolysaccharide lipopolysaccharides (LPS) to catalyze inflammagenesis, including via β-amyloid formation. We discuss various co-existing features in RA, including iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. We review literature and provide coherent evidence that an aberrant blood microbiome in RA has a major involvement in the development, progression, and therefore over-all etiology of the disease.