What does Faecal Microbiota Transplantation consist of?

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Faecal microbiota transplantation (FMT) is a procedure to transfer faecal microbiota from a healthy person’s processed stool sample into the intestinal tract of a person with a certain disease. 

FMT has been shown to be around 80-90% effective after a single intervention and this percentage increases if repeated a second time. 

What is Faecal Microbiota? 

Faecal microbiota is the set of microorganisms (mainly bacteria, viruses and fungi) found in the intestine which play an essential role in the proper functioning of the body. It is also known as intestinal microbiota. 

When in balance (diverse and proportionate community), this microbiota contributes to the synthesis of vitamins, the digestion of food, the regulation of the immune system and protection in front of infection. Sometimes this balance of microbiota can be lost for different reasons, such as the use of antibiotics, consumption of certain medications, an inadequate diet, alcohol consumption or stress. 

All of this may be associated with different symptoms and diseases as diarrhoea, intestinal infections, irritable bowel syndrome, immune system disorders, inflammatory bowel diseases, colorectal cancer, liver diseases, allergies or type 2 diabetes. However, this relationship is still under study.

In some of these cases, faecal microbiota transplantation could restore their balance in the colon. 

Which diseases may necessitate a Faecal Microbiota Transplantation? 

The most common cause of diarrhoea among patients is Clostridioides difficile (C. difficile) infection. This bacterium can take advantage of microbiota weakened during treatment with antibiotics, chemotherapy or radiotherapy to grow in the intestine, producing diarrhoeal symptoms which can become very serious. 

Currently, faecal microbiota transplantation is recognised in national and international guidelines as the treatment of choice for recurrent C. difficile infection, as it is the most effective way to recover the best possible healthy microbiota.  

Who can be a Faecal Microbiota donor? 

To be an intestinal microbiota donor, you must pass an exhaustive screening process to guarantee the safety of the recipient. It starts with potential donors filling in a form about their medical history and healthy habits, followed by a blood test and stool analysis. 

If suitable, the donor can voluntarily provide samples for a period of 2 months, these are then processed fresh in the laboratory and kept in quarantine. After this period, the donor goes through a second screening before the previous samples can be released, to guarantee the safety of the treatments. This process can be repeated as many times as the donor wants. All donations are done altruistically and no financial compensation is received. 

How is Faecal Microbiota Transplantation performed? 

Currently, the most effective and main route of administration for a faecal microbiota transplantation (FMT) is through a colonoscopy (an endoscopic colon exploration technique).  The sample of healthy microbiota (approximately 250 ml) has to be deposited in the patient's colon; whereupon, the patient has to rest for an hour. 

To avoid a colonoscopy, treatment with capsules taken orally has been successfully tested; although the number of capsules to ingest can vary between 5 and 20. 

How should the recipient prepare beforehand? 

Patient preparation depends on the method of administration of the faecal microbiota transplantation. For a colonoscopy, the patient follows the protocols prepared for this procedure. No prior preparation is needed for oral administration. 

What should you do after receiving a Faecal Microbiota Transplantation? 

If administered by colonoscopy, the respective indications for this procedure must be followed; while in the case of taking capsules, there are no further indications. In both cases, patients are recommended to continue with their usual routine once the procedure is over. It is recommended to avoid taking antimicrobial drugs after treatment. 

What are the possible complications of Faecal Microbiota Transplantation? 

Faecal microbiota transplantation is a safe, short-term procedure. The main associated symptoms, such as abdominal distension, flatulence and nausea, are minor and last just a few days. No significant health problems have been reported in the long term. 

Substantiated information by:

Andrea Aira Gómez

Published: 8 January 2024
Updated: 8 January 2024


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