Cindy Boer

Microbiome Composition, Joint Pain and Inflammation | 241 5.2 ▲ Figure 2: Proposed hypothetical me pathophysiological mechanism explaining the association between the gut microbiome (Streptococcus spp.), knee WOMAC pain and knee effusion . No causality has been established between Streptococcus spp. abundance and OA-related knee pain, however, if such causality exists, we propose the following model: Members of the Streptococcus spp. are known to produce metabolites and membrane vesicles, which both may interact with host cells. These bacterial products can pass the gut-blood barrier, and possibly either a target the knee joint through activation of macrophages in the synovial lining, leading to joint inflammation and damage, or b enter the circulation, activate macrophages to pro-inflammatory macrophages, which may trigger a low-grade systemic inflammatory state, invoking or exacerbate joint inflammation and damage, leading to increased knee pain