What is a faecal microbiota transplant (FMT)?
A faecal microbiota transplant (FMT), or a gut microbiome transplant (GMT), is a medical treatment in which faecal matter from a healthy donor is processed and administered into a patient's gastrointestinal tract.
The primary purpose of FMT is to stabilise the microbiome by reintroducing beneficial microbes. In other words, FMT involves transferring the entire gut ecosystem from a thoroughly vetted donor to a patient to restore balance and cure disease.
How it works
FMT seeks to re-establish the physiological microbial equilibrium in the gastrointestinal tract, thereby modulating the gut environment and potentially influencing a patient’s metabolism, immune response, and gut barrier function.
Donor faecal material is meticulously screened and processed. It can be administered via multiple routes such as colonoscopy, nasogastric tube, oral capsules, or an enema, each with distinct advantages and clinical considerations.
Why do you need a faecal microbiota transplant (FMT)?
The most common disease that can be treated with FMT is recurrent, severe Clostridioides difficile (C. diff) infection. Many people have C. diff bacterium as a natural part of their gut microbiome but have no issues with it because of good bacteria that keep the C. diff bacteria in check.
However, when some people receive long-term antibiotic treatment, it can disrupt gut flora by eradicating the good bacteria along with the bad in their gut microbiome, causing the C. diff bacteria present to cause an infection that, in severe cases, can lead to watery diarrhoea 10 – 15 times daily, severe dehydration, a swollen belly, fever, nausea and more, making it life-threatening.
However, the therapeutic applications of FMT are broadening, with ongoing research investigating its efficacy in various other conditions, such as:
Who should not undergo a faecal microbiota transplant (FMT)?
People might not be able to get an FMT if their immune system isn’t strong, if they have heart conditions that aren’t stable, or if they’re experiencing intense bleeding in their digestive system.
Additionally, there are some patients who may be considered high-risk for adverse events. These include patients with IBD, ulcerative colitis (UC), Crohn’s disease, recipients of recent organ transplants, and other immunocompromised patients.
In these cases, it is advisable to seek a clinician’s opinion.
What are the risks and complications of a faecal microbiota transplant (FMT)?
It is generally considered a safe procedure for most people, but like any medical procedure, it carries certain risks and potential complications.
If you are receiving FMT through a colonoscopy, some temporary side effects might include:
- Swelling and gas in the abdomen
- Pain from air getting stuck in the large intestine during the treatment
- Bowel irregularity as a result of medicine to prevent diarrhoea
- Slight escape of the transplant fluid from the rectum* Common hazards from a colonoscopy, which include contamination, haemorrhage, a rupture or hole necessitating surgical intervention, and dangers associated with the use of anaesthesia
Other risks of FMT include:
- Infection. Although the stool used in FMT is thoroughly tested, there's a slight risk of transmitting infections from the donor to the recipient.
- Unexpected body responses. Rarely, individuals might experience unexpected changes in their body due to the new gut bacteria, like alterations in immune system response or metabolism.
- Long-term risks. The long-term risks of FMT aren’t fully understood yet. Changes in the gut bacteria could potentially impact various aspects of health over time, which researchers are still studying.
How do you prepare for a faecal microbiota transplant (FMT)?
Preparation entails a thorough clinical evaluation of both donor and recipient. The recipient may undergo bowel cleansing and possibly a short course of antibiotic pretreatment to optimise the gut environment for microbial engraftment.
Donor screening is paramount, involving comprehensive testing for infectious agents and metabolic assessments to ensure the safety and efficacy of FMT.
What can you expect in a faecal microbiota transplant (FMT)?
Step 1: Donor screening
The first step involves selecting a suitable donor. Donors undergo a thorough evaluation involving physical checks and an in-depth medical background assessment to confirm they:
- Are free from chronic illnesses
- Don't suffer from inflammatory bowel disease or colorectal cancer
- Aren't on persistent medications
- Haven't participated in activities that increase their risk of infectious diseases
- Haven't consumed antibiotics in the 3 months before donating or during the donation time frame
- Have healthy levels of cholesterol, as high low-density lipoprotein (LDL) cholesterol levels can negatively affect the microbiome
Furthermore, they are tested through blood and faecal examinations for various infections, including:
- Hepatitis types A, B, C, and E
- STDs like HIV and Syphilis
- Microbes that include Clostridioides difficile (C. difficile), worms, parasites, SARS-CoV-2, and bacteria that cause diarrhoea like E. coli, Salmonella, and Vibrio cholera.
Family and friends who live in the same environment and have similar lifestyles typically won’t qualify as donors, as the gut microbiome is heavily affected by diet, the environment, and lifestyle factors.
A thorough review of the donor’s and patient’s medical history, current medications, and overall health status will be conducted to mitigate risks and optimise the procedure's success.
A stool sample will be collected from the chosen donor. This sample will serve as the source of the healthy gut microbiota to be transplanted.
Step 3: Sample processing
The collected stool sample will then be processed in a laboratory in a specially designed chamber to keep the bacteria viable. It is typically homogenised with saline and filtered to remove food and other large debris. After concentrating the remaining stool, it is combined with glycerol to create a liquid suspension containing the live microbiota.
Step 4: Recipient preparation
The recipient will be prepared for the FMT. This involves a bowel cleanse and antibiotics to ensure that the transplanted microbiota can establish itself effectively in the recipient's gut.
Step 5: Transplantation
The processed donor stool suspension will be administered to the recipient. This can be done through various methods, such as oral capsules, nasogastric or nasoenteric tubes, colonoscopy, or upper endoscopy, depending on the patient's condition and the healthcare provider's preference.
In our hospital, a colonoscopy is the preferred method of administering faecal microbiota transplantation. It remains the treatment method that allows optimal placement of the donor microbiome at the desired engraftment location (terminal ileum and caecum).
Step 6: Follow-up
Post-procedure, patients may be monitored for immediate complications or side effects, with tailored dietary and medication advice provided based on the individual's medical status.
Follow-up appointments will then be scheduled to track the patient’s recovery and the impact of the FMT on their gastrointestinal health.
Care and recovery after a faecal microbiota transplant (FMT)
Post-FMT care entails close monitoring to evaluate the efficacy and any potential adverse effects alongside strategic dietary management to support microbial colonisation and stability.
