Fig. 1.

Potential mechanisms by which FMT may be beneficial to those undergoing cancer therapy. Delivering a diverse microbiome serves to promote microbial competition, thus controlling pathogen expansion and reducing the risk of infectious complications. Similarly, FMT has been shown to restore short chain fatty acid profiles, thus aiding epithelial repair and intestinal homeostasis. FMT may also be used to promote a unique microbial phenotype known to induce preferable treatment responses; an approach increasingly investigated for immunotherapy-colitis and efficacy. Promoting microbial diversity via FMT is also likely to enhance natural barrier defenses, including anti-microbial peptides, tight junction assembly/integrity, mucus production and epithelial proliferation. These hold great promise in promoting recovery from acute mucosal injury and preventing bacterial translocation; each of which are key initiating factors in GvHD development. FMT efficacy is also considered to occur via immunomodulating, promoting TLR equilibrium and dampening aberrant inflammatory signaling.