CAR-T Cell Therapy and Gut Microbiota Modulation in Multiple Sclerosis: Emerging Therapeutic Strategies and Current Limitations.

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system (CNS) characterized by the destruction of the myelin sheath around nerve cells. The prevalence and serious consequences of MS highlight the shortcomings of existing treatments and the importance of developing innovative therapeutic approaches. Based on successful pilot studies in patients and an experimental autoimmune encephalomyelitis (EAE) mouse model, CAR-T cells offer a novel therapeutic mechanism by directly targeting and eliminating B cells, overcoming the shortcomings of antibody-mediated B cell depletion, which is unable to penetrate deep into the CNS. Recent discoveries have also revealed an important role for the gut microbiota in maintaining immune homeostasis. In a state of homeostasis, there is a symbiotic relationship between host factors and the microbiota that helps to maintain a healthy state. However, alterations in the composition and function of the gut microbiota, known as gut dysbiosis, can disrupt this homeostasis. The microbiota, through its metabolites, can influence not only internal processes in the gut but also the CNS in MS. Therapeutic interventions that help restore the balance of the gut microbiota may be a promising additional treatment to existing therapies to alleviate symptoms and promote remission in patients with MS.