Yoga and Neuroimmune Regulation in Autoimmune Disorders: A Mechanistic Review of Stress Signalling, Autonomic Function, and Immune Tolerance

Background: Autoimmune disorders arise from interactions among genetic susceptibility, immune dysregulation, neuroendocrine and autonomic signalling, and environmental exposures. Yoga combines physical postures, regulated breathing, meditative attention, and relaxation, and may influence several of these domains. It remains uncertain whether yoga modifies autoimmune disease biology or primarily improves symptoms and function. Objective: To describe the mechanisms by which yoga could influence stress signalling, autonomic function, inflammatory biology, and immune tolerance in autoimmune disorders, and to appraise the clinical evidence for each mechanistic link. Methods: This focused narrative review (not a registered systematic review) synthesizes clinical studies of yoga in autoimmune disease, evidence syntheses, and mechanistic literature on the hypothalamic–pituitary–adrenal axis, autonomic–immune communication, and regulatory T cells. Evidence is classified as direct clinical, indirect human, or mechanistic rationale. Results: The strongest mechanistic signals come from short randomised trials in rheumatoid arthritis (RA), in which yoga added to usual care was associated with changes in disease activity, cytokines, neuroendocrine-associated markers, and T-cell subsets; one trial (n = 64) reported lower T helper 17 (Th17) and higher regulatory T-cell proportions at eight weeks. These findings do not show that yoga acted through those pathways: programmes were multicomponent, comparators were mostly not attention-matched, one formal mediation analysis did not support mediation, and durable tolerance was not tested. Meta-analyses suggest possible benefit for RA function and disease activity, but pooled inflammatory-marker effects are inconsistent and certainty is low. Evidence in multiple sclerosis (MS) concerns fatigue and function, and evidence in systemic lupus erythematosus (SLE) is preliminary. Direct evidence that yoga engages a vagal anti-inflammatory reflex in autoimmune patients is insufficient. Conclusions: Yoga may be a useful adjunct for well-being, fatigue, function, and stress management when adapted to disease limitations and used alongside standard treatment. It should not be represented as a proven disease-modifying therapy or as restoring immune tolerance. Mechanistic claims require larger, preregistered trials with active comparators, standardised exposure, repeated pathway measures, and long-term disease outcomes.