Long-term impact of fecal transplantation in healthy volunteers

Abstract

Background Fecal microbiota transplantation (FMT) is now approved for the treatment of refractory recurrent clostridial colitis, but a number of studies are ongoing in inflammatory bowel diseases, i.e., Crohn’s disease, nonspecific ulcerative colitis, and in other autoimmune conditions. In most cases, the effects of FMT are evaluated on patients with initially altered microbiota. The aim of the present study was to evaluate effects of FMT on the gut microbiota composition in healthy volunteers and to track long-term changes. Results We have performed a combined analysis of three healthy volunteers before and after FMT with frozen capsules, followed by evaluation of their general condition, adverse clinical effects, changes of basic laboratory parameters, and several immune markers. Intestinal microbiota samples were evaluated by 16S rRNA gene sequencing (16S seq) and shotgun sequencing (or whole-genome sequencing – WGS). The data analysis demonstrated the profound shift towards the donor microbiota taxonomic composition in all volunteers. Following FMT, all the volunteers exhibited gut colonization with donor gut bacteria, and persistence of this effect for almost ~1 year of observation. Transient changes of immune parameters were consistent with suppression of T-cell cytotoxicity. FMT was well tolerated with mild gastrointestinal adverse events and systemic inflammatory response in one volunteer. Conclusions The FMT procedure leads to significant long-term changes of the gut microbiota in healthy volunteers with the shift towards donor microbiota composition, being relatively safe to the recipients without long-term adverse events.