Prevotella also activates the TLR-2 receptor of the intestinal epithelial cells and stimulates the release of proinflammatory cytokines such as IL-1β, IL-6, and IL-23 and promotes the activation of Th17 cells that leads to massive production of IL-17, inflammation, and initiation of RA [72] (Figure 1). Here, IL17A is linked to rheumatoid arthritis.