The human body contains 10 bacterial cells for every human cell. That’s right. Our bodies have 10 times more bacteria than human cells. 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. Fortunately, a promising therapy called Fecal Microbiota Transplantation may help patients suffering from microbiome-related conditions.
Fecal Microbiota Transplantation (FMT) is a new treatment that has been shown to be over 90% effective for treating C. difficile infection in patients who had previously failed to recover with antibiotic therapy. During FMT, a fecal preparation from a carefully screened, healthy stool donor is transplanted into the colon of a sick 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 helpful bacteria and allowing C. difficile to thrive, as it 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 fever. 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.