In this interview, Marika Falcone of San Raffaele Hospital in Milan discusses the growing evidence linking the gut microbiome to extra-intestinal autoimmune diseases, with a focus on multiple sclerosis and type 1 diabetes. Recent research has shown that self-reactive T lymphocytes involved in these disorders are modulated in the gut, highlighting the central role of the commensal microbiota in shaping immune responses beyond the intestine.

Falcone explains that her group has identified alterations in microbiota-derived metabolites in patients with multiple sclerosis and has also shown that the gut microbiota can directly promote the activation of autoreactive T cells, which then migrate to peripheral organs and contribute to disease onset and progression. These findings open important clinical and therapeutic perspectives. Current strategies under investigation include the use of probiotics, dietary interventions, and fecal microbiota transfer, not only from healthy donors but potentially also from patients who respond well to immunoregulatory therapies.