This study is a phase 2/3, double-blinded, randomized controlled trial (RCT) in which 80 adults with TRD being treated with an approved antidepressant medication will be assigned to either FMT capsules or identically appearing placebo capsules. Participant will be followed for f for 14 weeks post FMT. This extended observation period will allow us to see, whether FMT leads to sustainable improvements in depression and changes in intestinal microbiome
The primary goals of this proof of concept clinical trial are to determine the effectiveness, safety and tolerability of oral FMT in adults with Treatment Resistant Depression (TRD).