Systematic Review

The Global Incidence of Faecal Microbiota Transplantation-related Adverse Events From 2000 to 2020

Cicilia Marcella; Bota Cui; Colleen R. Kelly; Gianluca Ianiro; Giovanni Cammarota; Faming Zhang


Aliment Pharmacol Ther. 2020;53(1):33-42. 

In This Article

Abstract and Introduction


Background: Faecal microbiota transplantation (FMT) is an effective treatment in C. difficile infection (CDI) and is currently being investigated in other diseases. There is concern around the safety of FMT and that side effects or complications may be under-reported in the medical literature.

Aim: To evaluate the safety of FMT by summarising the overall reported Adverse Events (AEs) over a 20-year period

Methods: We searched EMBASE, MEDLINE, and Cochrane Library databases, and CNKI and Wanfang Data from January 2000 to April 2020. All original studies reporting FMT-related AEs were considered for inclusion. FMT-related AEs were further classified as delivery-related or microbiota-related.

Results: Based on the inclusion criteria, 129 studies, which included 4241 patients (5688 FMT courses), were finally eligible. The most common indication for FMT was CDI. Overall, FMT-related AEs were observed in 19% of FMT procedures. The most frequently reported FMT-related AEs were diarrhoea (10%) and abdominal discomfort/pain/cramping (7%). FMT-related serious adverse events (SAEs), including infections and deaths, have been reported in 1.4% of patients who underwent FMT (0.99% microbiota-related SAEs). Four of five FMT-related deaths were reported in patients receiving FMT via the upper gastrointestinal route. Importantly, all reported FMT-related SAEs were in patients with mucosal barrier injury.

Conclusion: Most FMT-related AEs were mild or moderate and self-limiting. Although FMT appears to be highly safe, its methodology should be improved to reduce both delivery-related AEs and, microbiota-related AEs.


The history of faecal microbiota transplantation (FMT) dates back to 300 AD in China, when severe diarrhoea, food poisoning and fever were treated by drinking fresh or fermented faecal water.[1,2] FMT is recommended in several international guidelines as an effective treatment option for recurrent CDI.[3–8] Moreover, increasing evidence supports the use of FMT in conditions beyond CDI, including inflammatory bowel disease (IBD),[9,10] chronic radiation enteritis,[11] liver disease,[12–18] antibiotic-associated diarrhoea in the critical patient,[19] multidrug-resistant bacteria colonisation[20,21] and immune checkpoint inhibitor-associated colitis.[22] It is being investigated in other conditions associated with alterations in gut microbiota such as irritable bowel syndrome (IBS),[23–25] constipation,[26] metabolic syndrome,[27] obesity,[28] autism,[29,30] epilepsy[31] and acute graft-versus-host disease.[32] Currently, there are about 400 registered trials of FMT around the world. Despite the benefits of FMT, core concerns remain around long-term outcomes and the potential for adverse events (AEs) related to FMT. It is important to understand the risks of FMT so that patients may be counselled appropriately before undergoing the procedure and so that post-FMT complications can be recognised and managed in a timely manner. Furthermore, awareness of potential FMT-related complications may drive development of improved treatment protocols. In the present study, we aimed to quantify and summarise the reported FMT-related AEs from the global English language medical literature and Chinese publications from 2000 to 2020.