Fecal Matter Transplant (FMT)

Fecal microbiota transplant (FMT) is a medical procedure in which processed stool from a screened donor is transferred into a recipient’s gastrointestinal tract with the goal of restoring microbial diversity and function. Clinically, FMT is an established treatment for recurrent Clostridioides difficile infection, but it has also been explored experimentally for a wide range of inflammatory, neurologic, and metabolic conditions because of the gut microbiome’s broad influence on immune, hormonal, and nervous-system signaling.

In PFS/PSSD/PAS discussions, interest in FMT comes from several overlapping hypotheses rather than a single mechanism. These include the role of gut bacteria in neurosteroid production and metabolism, interactions between the microbiome and GABAergic and stress-response pathways, emerging evidence that gut microbes can influence androgen metabolism and androgen receptor signaling, and the microbiome’s ability to affect epigenetic regulation and long-term gene expression patterns. Because these syndromes are often described as involving persistent, system-level dysregulation rather than isolated hormone levels, some people view microbiome-focused interventions as a way to address a deeper regulatory layer.

Anecdotes (Community Reports):

https://youtu.be/mQAnwC6dTkE?si=GvO78evJuHcAbRSB

https://www.reddit.com/r/PSSD/comments/1eq591x/fmt_fecal_transplant_update_almost_a_year_later/

https://www.reddit.com/r/PSSD/comments/1ksg9g4/fmt_experiences_please_let_me_know_if_it_worked/

How to Interpret This Page

This page summarizes community anecdotes and informal observations, not medical evidence. “Improvement” means a person reported feeling better after an intervention; it does not establish that the intervention caused the change or that it will apply to others. Outcomes are frequently influenced by multiple variables (time, stopping other triggers, concurrent treatments, donor differences, procedure methods, diet, and overall health), and reporting bias is common. Some interventions described in improvement stories are also associated with neutral outcomes or flares in other reports. Use this page as a starting point for research and discussion with a licensed clinician—not as medical advice or a recommendation to pursue treatment.

Community Reports: Mixed Outcomes & Variable Risk Signal

Within PFS/PSSD/PAS communities, fecal microbiota transplant appears in a small but notable set of anecdotesdescribing improvement, and in a few cases very large improvement or “full recovery” claims. These reports often emphasize changes in baseline energy, stress tolerance, cognition, mood, or a sense of systemic stabilization. At the same time, many others report little to no meaningful improvement, even after multiple transplants or extended follow-up. Overall, outcomes appear highly variable rather than consistently positive.

While FMT is often perceived as lower risk for permanent worsening compared with aggressive pharmacologic or hormonal interventions, it is not a benign or DIY approach. The procedure carries real medical risks (including infection transmission, gastrointestinal complications, immune reactions, and unpredictable systemic effects), and outcomes depend heavily on donor selection, screening quality, preparation, route of administration, and recipient health status. Some individuals report transient flares or destabilization even when long-term harm is uncommon. For these reasons, FMT is generally viewed as a high-complexity, clinician-supervised intervention, not a casual experiment, and lack of benefit appears to be common despite occasional dramatic anecdotes.

Evidence Basis

Clinical literature on fecal microbiota transplant for approved indications (e.g., recurrent C. difficile); emerging research on the gut–brain axis, microbiome–neurosteroid interactions, immune signaling, and epigenetic modulation; anecdotal community reports (online forums, self-reports).

No controlled studies demonstrate efficacy or safety of FMT specifically for PFS/PSSD/PAS.