Inflammatory bowel disease is a common gastrointestinal (GI) disorder affecting approximately 10%–15% of the worldwide population,1 characterized by chronic abdominal pain and altered bowel habits. Although the pathophysiology of IBD remains still largely unknown, growing evidence suggests that factors such as food habits, antibiotics, and gender, as well as psychosocial events,2 may be a trigger in genetically susceptible individuals.3,4 In the recent years, an important role of the gut microbiota in IBD has been recognized. In the healthy status, the gut microbiota actively interacts with the human host to modulate several physiological functions such as gut development,5 immune responses,6,7 resistance to pathogens,8and brain development and functions.9,10 Changes in bacteria composition and number, known as “dysbiosis,” have repeatedly been observed in IBD patients and are now recognized as a key element in gut inflammatory processes.11–13 Dysbiosis of the gut microbiota is characterized by a significant reduction of obligate anaerobes such as members of the phyla Bacteroidetes and Firmicutes and a sharp increase in facultative anaerobes such as the phyla Actinobacteria and Proteobacteria, such as Escherichia coli. A decrease in obligate anaerobes results in the release of anti-inflammatory compounds, which causes increased inflammation.14,15 Therefore, the dysbiosis correction has been considered an attractive therapeutic approach. FMT can reduce bowel permeability by increasing the production of short-chain fatty acids, especially butyrate, which helps in maintaining the integrity of the epithelial barrier and thus decreases the severity of the disease. FMT can also restore immune dysbiosis by regulating the inflammatory markers by inhibiting the activity of T cells, leukocyte adhesion, and the production of inflammatory factors.16 Although microbiome-based therapies, such as probiotics and antibiotics, failed to be effective in IBD, recently, FMT is gaining a new life as a therapeutic option for the patients with a disturbed gut ecosystem.

FMT is a procedure in which fecal or stool matter is collected from a healthy donor and placed into a patients’ GI tract to correct the dysbiosis and to restore healthy conditions.17 FMT has already been successfully used for the treatment of recurrent Clostridium difficile infection (rCDI) resistant to conventional antibiotic therapies,18,19 with an efficacy >90%.20–23 For this reason, it is now being considered as an experimental therapy in IBD and labeled by the Food and Drug Administration as Investigational New Drug in 2016.24