Exosomes, small molecules with phospholipid bilayer structures derived from cell membranes, usually contain many biomacromolecules, such as proteins, mRNAs, and miRNAs. Exosomes have been verified to be among the most important mediators of material and information exchange within or between individuals. In recent decades, exosomes have attracted increasing attention from researchers. In this review, the structure, methods of separation and identification, and cell origination of exosomes are described in detail. The potential applications of exosomes, such as anti-inflammatory and immunomodulatory effects, tissue damage repair and regeneration, antioxidant function, drug delivery, and cancer therapy, are summarized. Food-derived exosomes from animals, plants and microorganisms have become a research hotspot. Exosomes carrying biomacromolecules are important mediators of signal transduction and regulation between cells from the same individual and between individuals of the same or different species. It is widely considered a promising intermediate for food nutrition and chronic disease prevention.

As a chronic inflammatory and autoimmune disease, rheumatoid arthritis (RA) leads to joint dysfunction and deformities due to joint inflammation, bone erosion, and cartilage destruction, potentially resulting in permanent disability, which significantly reduces patients’ quality of life. Compared with refined grains, whole grains retain components such as the endosperm, germ, and bran, which are rich in higher levels of phytochemicals and nutrients. Recent studies suggest that the components in whole grains may play essential roles in the alleviation of RA. This review summarizes the potential effects of whole grain ingredients on alleviating RA via the inhibition of synovial fibroblast migration, cartilage degradation, and osteoclast activity and further elaborates their mechanisms that phytochemicals and nutrients in whole grains inhibit RA via anti-inflammatory, antioxidant, and immune system modulation pathways. We anticipate that nutritional interventions with whole grains may offer new avenues for the prevention and treatment of RA.