Challenges of Screening Prospective Stool Donors for Fecal Microbiota Transplantation

Despite high efficacy rates, significant costs and logistical challenges associated with procuring stool from healthy donors for fecal microbiota transplantation (FMT) have presented barriers to broader institutional adoption and limited the availability of this life-saving treatment. Published outcomes for donor screening programs report donor deferral rates between 90% and 96%. Due to the paucity of FMT donor screening data, a secondary analysis on a cohort of previously screened donors (n = 7,968) was conducted to provide a synopsis of the observed trends and rationales for prospective stool donor deferrals. Upon completion of the evaluation, 1.7% of prospective donors (n = 134) qualified for stool donation. Over 50% of donors who completed the online pre-screen were deferred, primarily for a body mass index of 30 kg/m² or greater (n = 1,516, 37.0%), logistics (n = 841, 20.5%), and travel history (n = 638, 15.5%). Despite pre-screening, 569 donors (72.8%) who completed the in-person clinical assessment were ultimately deferred due primarily to potentially microbiome-mediated diseases (n = 187, 32.9%). A notably small portion of donors (n = 46, 25.6%) were deferred during the laboratory assessment process suggesting the clinical assessment was effective at deferring donors at higher risk for transmissible diseases. Donors lost to follow-up throughout the screening process presented a significant challenge and contributed to a notable (n = 3,117; 39.1%) portion of donor attrition. Findings were used to support recommendations for improving prospective stool donor screening programs and to provide suggestions for future research.