The role of fecal microbiota transplantation in the treatment of neuropsychiatric disorders: emphasis on schizophrenia

The gut-brain axis constitutes a bidirectional communication system between the gastrointestinal tract and the central nervous system, integrating neural, endocrine, immunological, and metabolic mechanisms. The gut microbiota plays a central role in this process by modulating neurotransmitters, cytokines, and bioactive metabolites, influencing cognitive, emotional, and behavioral functions. Alterations in its composition, known as dysbiosis, have been associated with various neuropsychiatric disorders, such as depression, anxiety, autism, and schizophrenia. In schizophrenia, dysbiosis contributes to chronic inflammation and dopaminergic imbalance, mechanisms relevant to the disease’s pathophysiology. In this context, fecal microbiota transplantation (FMT) emerges as a promising therapeutic strategy, already established in the treatment of recurrent Clostridioides difficile infection. Preclinical evidence demonstrates that FMT can restore microbial diversity, modulate immune responses, and reduce neuroinflammation, leading to improvements in behaviors associated with schizophrenic symptoms. In humans, data are still limited, but case reports and pilot studies suggest potential clinical benefits. It is concluded that, although FMT represents an innovative and relevant alternative for managing neuropsychiatric disorders, particularly schizophrenia, the lack of standardized protocols and the scarcity of robust clinical trials still limit its application. Further research is essential to establish safe and effective guidelines.