The proinflammatory cytokines IL-23, TNF-α, and IL-6, induced by S. copri-OMVs in monocyte-derived macrophages, are related to the generation of IL-17-secreting Th17 cells and a shift in the Th17/Treg balance—a hallmark of autoimmune diseases such as RA [70]. Here, IL17A is linked to rheumatoid arthritis.