Immune and inflammatory responses in microgravity: implications and therapeutic approaches

Spaceflight exposes the human body to microgravity, isolation, and radiation, which collectively disrupt physiological homeostasis, particularly affecting the immune system. Microgravity significantly impairs both innate and adaptive immune responses by altering immune cell formation, activation, trafficking, and cytokine production. These disturbances manifest as an overall shift toward an immunosuppressive phenotype, increased oxidative stress, and transcriptional reprogramming of immune cells. Pharmacological agents, including natural antioxidants, flavonoids, and bioactive polysaccharides, have demonstrated anti-inflammatory and immune-restorative effects in microgravity models. In this review, we highlight the molecular mechanisms of immune dysfunction in microgravity and explore current potential therapeutic approaches to ensure safe long-duration space missions.