What is Fecal Microbiota Transplantation?
The human body contains 10 bacterial cells for every human cell. This vast, largely unexplored bacterial community known as the microbiome has been linked to many aspects of human health, from gastrointestinal diseases to obesity. Importantly, disrupting the microbiome with antibiotics can cause disease by wiping out the helpful bacteria in our guts.
Fecal Microbiota Transplantation (FMT) is an innovative treatment that has – in randomized, controlled clinical trials – resolved between 80 and 91 percent of infections caused by recurrent C. difficile that does not respond to antibiotics. During FMT, a fecal preparation from a carefully screened, healthy stool donor is transplanted into the colon of the patient. There are multiple routes of administration (e.g., via colonoscopy, naso-enteric tube, capsules), each of which has unique risks and benefits.
How does FMT work?
Though the mechanism has yet to be determined, it is believed that FMT works by repopulating the patient’s microbiome with diverse microorganisms that competitively exclude C. difficile.
In a healthy gut community, C. difficile is out-competed by many different bacterial species. However, receiving antibiotic treatment disrupts this ecosystem by killing those protective bacteria. C. difficile forms spores that are resistant to antibiotics. No longer outcompeted, this pathogen establishes itself in the gut and produces toxins that leave patients suffering from severe diarrhea, abdominal pain, and, often, fever. With an infusion of bacteria from a healthy donor's stool, the C. difficile is again out-competed.
Researchers are also exploring FMT's potential role for treating other gastrointestinal diseases, such as IBS and Crohn's Disease.
Although FMT is a powerful tool for treating C. difficile infection, there are also important risks. Stool is a complex living mixture of bacteria and other organisms. While stool donors can be carefully screened for known infectious agents, there is always a risk that the tests might fail to detect a pathogen. There are also procedural risks associated with receiving an FMT by colonoscopy or other methods of administration.