Fecal microbiota transplantation (FMT), initially successful against recurrent C. difficile infections, is attracting research attention for treating diverse conditions including alopecia, depression, Parkinson’s, and dementia. A surge in publications—1,300 in 2024 alone—explores its potential across neurological, autoimmune, metabolic, and psychiatric disorders. The method’s role in modulating gut microbiota highlights complex systemic effects beyond infection control, underpinning rapid growth in clinical and preclinical investigations.