For recurrent C. difficile infection, FMT is the best-proven option: it rebuilds colonization resistance, and the diarrhea often clears within days.
When inflammatory bowel disease doesn't fit neatly into colitis or Crohn's, this profile guides a cautious, combined approach to FMT.
In ulcerative colitis, FMT can bring remission for a subset of patients when it draws on multiple donors and weeks of patient consolidation.
In autism, FMT remains investigational: improving gut symptoms is a realistic goal, behavioral change far less certain, and every step is shared with the care team.
In Crohn's disease the response to FMT is weaker than in colitis, so it stays investigational and shows the most promise in the biologic-naive, ileocolonic subgroup.
In irritable bowel syndrome the response is highly individual: the diarrhea-predominant type responds best, and here a single, carefully chosen super-donor works better than a pool.
In multiple sclerosis, FMT is investigational: it targets immune balance and gut symptoms but never replaces disease-modifying therapy and must be guided alongside your neurologist.
In Parkinson's disease, FMT is investigational and most promising early on: constipation eases most reliably, while it complements rather than replaces standard therapy.
In metabolic syndrome and type 2 diabetes, FMT is still experimental: the strongest, immediate move is a fiber-rich Mediterranean diet that improves insulin sensitivity.