Strict quality control and screening should be an essential part of the FMT procedure, as an increase in serious adverse events in the context of investigational FMT could lead to harder regulations and make access more difficult for patients, which would likely increase the demand for unregulated or ‘at-home’ FMT. However, obtaining safe stool for faecal transplantation is not trivial. In the US, a not-for-profit stool bank, OpenBiome (http://bit.ly/30nsE1B), was founded in 2012 and now supplies stool for most of the US investigational FTM procedures. Stool donors are selected through strict health screens and are closely monitored; additionally, samples are sequenced to screen for pathogens and to determine their composition, and then quarantined to ensure they were not obtained during the seroconversion period of an infectious disease. Aliquots of every stool preparation are kept for future reference in case of an adverse event.