Impact of Regular Yoga and Meditation on Immune Cell Populations: A Small-Sample, Single-Arm, Pre-Post Interventional Pilot Study

Background Immunity is the body's ability to resist infectious diseases and is regulated by the immune system, which is divided into innate immunity, with an immediate response, and adaptive immunity, which is more specialized and effective. Lymphocytes, such as CD4+, CD8+, and CD19+, are part of adaptive immunity, while monocytes/macrophages, CD14+, are phagocytic cells of the innate immune system and maintain homeostasis. Objectives The objective of this study was to evaluate the effect of a short-term yoga and meditation intervention on specific immune cell populations (CD4+, CD8+, CD19+, and CD14+) in healthy adults practicing yoga, using a pilot pre-post study design. Methodology A prospective pre-post pilot study was conducted in five healthy adult participants who were regular practitioners of yoga and meditation and attended a 15-day meditation retreat. Peripheral blood samples were collected before and after the intervention. Immune cell populations, including CD4+ T lymphocytes, CD8+ T lymphocytes, CD19+ B cells, and CD14+ monocytes, were quantified using flow cytometry following standard Ficoll-based peripheral blood mononuclear cell isolation. Data normality was assessed using the Shapiro-Wilk test, and paired statistical analyses were performed to evaluate changes between pre- and post-intervention measurements. Results An increase in immune cell populations, including CD4+ T lymphocytes, CD8+ T lymphocytes, CD19+ B cells, and CD14+ monocytes, was observed following the intervention compared to baseline, with statistically significant differences (p<0.05). Conclusions Short-term yoga and meditation practice were associated with increases in adaptive and innate immune cell populations in this pilot study. These results suggest a potential link between regular practice and immune response, but larger controlled studies are required to draw definitive conclusions.