A fecal microbiota transplant (FMT) is a procedure where fecal matter, or stool, is collected from a healthy donor and transplanted to a recipient.
Its purpose is to replace good bacteria in the colon and help restore the individual back to good health.
While it may sound like an extreme approach, FMT provides astonishing results when used appropriately.
This article reviews how FMT works, the risks involved, and who may benefit. You’ll also learn about the future applications of this intriguing therapy.
What is a Fecal Transplant?
A fecal microbiota transplant (FMT) is also called a fecal matter transplant or stool transplant.
FMT takes the stool of one person and places it another to help change the recipient’s microbial (gut health) population and improve their health.
Because stool is composed of around 50% bacteria, transplanting it to the donor recovers and supports a healthy bacterial environment in the gut (large intestine).
This procedure dates back as far as fourth-century China by physician Ge Hong, who used it as a remedy for severe diarrhea and food poisoning. However, FMT only appeared in United States medical literature in the past 60 years (1).
In the past decade, FMT has received even more popularity and media coverage as studies confirm its effectiveness. In 2014, the Cleveland Clinic named FMT one of the top medical innovations, amounting to an ever growing push for clinical trials and new applications.
How It Works
After a rigorous screening process to collect healthy stool, the sample must be properly prepared prior to transplantation.
The sample is first diluted 2.5-5 times the volume with saline, water or milk, and then homogenized in a blender and filtered.
Thereafter, a variety of transplantation methods are available to administer the sample. Methods include colonoscopy, enema, flexible sigmoidoscopy, or ingestion of capsules.
There’s currently no definitive evidence supporting the superiority of one method over another (2).
Summary: A fecal microbiota transplant (FMT) transfers the stool of a healthy donor into a recipient to help improve their microbial environment. It’s documented use in the United States dates back to 1958, with countless studies and innovations emerging ever since.
Who Donates Their Feces?
Strict guidelines are in place to identify appropriate stool donors and reduce risks associated with this procedure.
Donors can be a friend, relative, or unrelated volunteer, however, he/she must meet the following criteria (3):
- Has not had any antibiotic exposure in the past three months
- No incarceration, tattooing or body piercing in past three months
- No history of drug use or high-risk sexual behavior
- Has not recently traveled to endemic areas
- No history of chronic diarrhea, constipation, IBD, IBS, colorectal polyps or cancer, immunocompromised, morbid obesity, metabolic syndrome, atopy, or chronic fatigue syndrome
- If the recipient has allergies, he/she must not ingest them several days prior to sample collection
Donors must also be thoroughly screened by their doctor for infections including (3):
- Blood tests: Hepatitis A, B, and C serologies; HIV; RPR; HIV, Syphilis
- Stool tests: Ova and parasites; C. difficile PCR; culture and sensitivity; giardia antigen; H pylori antigen, Isopora, Rotavirus
It can be tough to get your hands on this pristine stool. A nonprofit called OpenBiome helps collect, analyze, store, and disseminate stool samples to hospitals across the U.S.
Their mission is to ease the public’s access to FMT and further this therapy’s research and applications. This stool bank only accepts 3% of applicants; quite picky with their poo!
Summary: A rigorous screening process to identify healthy stool samples is in place to protect donors from potential harm.
Who Benefits From FMT?
While the research is promising, as of 2013 FMT is only FDA-approved to treat recurrent C. difficile infection.
Other potential applications are still considered investigational. Emerging areas of research are focusing on FMT for autism, metabolic syndrome, fibromyalgia, Parkinson’s disease and multiple sclerosis.
Recurrent C. Difficile
C. difficile is a serious infection resulting as a complication of antibiotic therapy, is on the rise throughout the world.
According to the Center for Disease Control, C. difficile infected 83,000 people in the U.S. as of 2011 and led to 29,300 deaths. Those over the age of 65 and/or suffering from a chronic illness are at higher risk of this infection (4).
After diagnosis the infection is treated with antibiotics. However, 30% of those treated experience a return of the infection within a few days to weeks (5).
A 2013 study of 16 C. difficile patients showed that FMT was even more effective than oral vancomycin, a common C. difficile antibiotic, in preventing recurrent infection. 81% had resolution of C. difficile-associated diarrhea after the first treatment (6).
FMT has an effectiveness rating for recurrent C. difficile at 85-90%, even after just one treatment. This makes it even more cost-effective than using multiple rounds of antibiotics (7).
Inflammatory Bowel Disease
FMT for inflammatory bowel disease (IBD) including Crohn’s Disease (CD) and Ulcerative Colitis (UC) is not FDA approved and limited to clinical trial settings.
While it may be a relatively safe procedure, effectiveness is not consistent across trials. For instance, a recent systematic review and meta-analysis of 18 studies on FMT for IBD reported a 36.2% remission rate. Variables including frequency of treatment, donor selection and microbiome analysis should be investigated in future FMT clinical trials (3, 8).
A study specifically on 75 patients with mild to moderate UC found remission rates of 24% with 6 weekly FMT sessions compared to 5% with placebo (9).
There have been limited and small, uncontrolled studies on FMT in Crohn’s disease, all with varying results. More clinical trials are underway to further investigate its safety and efficacy.
It appears that IBD is more complex to treat than C. difficile, but researchers are hopeful of this therapy’s use in the future.
Irritable Bowel Syndrome
Despite the effectiveness of the low FODMAP diet to address Irritable bowel syndrome (IBS) symptoms, many seek additional treatment options.
The benefits of FMT was observed in 13 IBS patients for 11-months. Patients reported 70% improvement in symptoms including abdominal pain, bowel habits, dyspepsia, bloating, and gas (10).
Currently, only preliminary trials and case reports are available for review. Randomized controlled trials are necessary to confirm FMT’s application for IBS.
Autism Spectrum Disorder
Autism is another condition that may benefit from FMT, but there’s no definitive advice at this time.
A recent small, open-label trial of 7-8 weekly doses of FMT on 18 children with autism spectrum disorder (ASD) assessed its impact on gastrointestinal health. The trial reported an 80% reduction in gut symptoms like constipation, diarrhea, indigestion and abdominal pain at the end of treatment, lasting for 8-weeks after treatment (11).
While these results appear promising, larger-scale, controlled trials are necessary for FMT’s future application in ASD.
Weight and Metabolic Syndrome
The idea of managing obesity and metabolic syndrome by managing one’s bacterial composition seems quite futuristic.
However, it may have some promising impact.While studies are still in their infancy and primarily from animals, they show a connection between body weight and FMT.
A case study report of 32-year old woman with recurrent C. difficile infection was successfully treated with FMT from a healthy, yet overweight stool donor. 16-months post-FMT, the woman unintentionally gained 34-pounds despite attempts at diet an exercise (12, 13).
One hallmark study tested FMT on insulin resistance, a component of metabolic syndrome. Stool from healthy, lean donors was transferred to obese individuals with type 2 diabetes.
Results were compared to subjects transferred their own stool and showed body mass stayed the same, but insulin sensitivity improved in those with FMT (14).
These findings need validation through more studies.
Summary: FMT is only approved to treat recurrent C. difficile infection. Other potential areas for future research of FMT include treating IBD, IBS, ASD, metabolic syndrome and obesity.
Steps Involved to Get a Fecal Transplant
There are few steps to know before getting FMT.
While specific details should be arranged by your doctor, keep in mind the following recommendations:
- Stop any antibiotic therapy two days before the procedure.
- Follow a liquid diet followed by an enema or laxative preparation the night before your scheduled procedure.
- Tell your doctors about any allergies and medications you take.
Keep in mind that approved doctors can only perform FMT for recurrent C. difficile. The doctor must file the procedure as an Investigational New Drug in order to use FMT for any other diagnoses.
To find practitioners nearby or clinical trials you may participate in, check out OpenBiome’s directory.
Summary: Schedule appropriate arrangements with your doctor if you plan on receiving FMT for recurrent C. difficile infection or in clinical trials.
Is It Safe to Do FMT Yourself?
Many are turning to Do It Yourself (DIY) FMT in a desperate attempt to improve their health.
Because FMT done at home is affordable, available, and low-risk (if safe stool samples are provided), popularity is on the rise.
Online resources like thepowerofpoop.com are helping people understand DIY FMT. They even help connect and screen potential stool donors. They do, however, post this disclaimer:
“These “Fecal Transplant At Home – DIY Instructions” are based on the experiences of one person, the anecdotal reports of others and questions most frequently asked by e-Patients. They are not medical advice. FMT is still considered an experimental procedure without known future consequences…”
The Fecal Transplant Foundation is a nonprofit advocating for more support and awareness around FMT. They estimate there are about 10,000 at-home FMT procedures in the U.S. each year. Numerous youtube videos and online forums vividly explain the steps involved with doing this procedure at home.
It goes like this…
“Basically some stool goes into a blender for a second mixed with saline. The concoction if needed is strained and then sucked into a large enema bulb. Enema is applied and you keep abdomen elevated and go through series of side, back, side motions + trying like hell to keep it in. The longer you can keep it in the better. Some struggle and lose it quite quickly but I will be determined to force it to stay in. The procedure can be easy but also messy and smelly and if you have a blowout.. So I intent to cover the bathroom in plastic, use gloves, mask etc to keep as sanitary as possible. I hope it works… “ – Reddit Forum
Completing FMT at home is not advised. The push for more research and FDA approval will hopefully decrease its prevalence in the coming years.
Summary: Because FMT is still considered experimental for most conditions, many turn to the DIY option. Online resources are available to guide people through this process. Complete at your own risk.
What Are the Risks of FMT?
There are potential risks with FMT if the procedure uses unhealthy stool samples.
Without proper sample screening, the transmission of any infection including HIV, Hepatitis and Syphilis is possible.
Additionally, there have been case reports of sudden weight gain, even when the sample comes from a normal weight individual.
When doing FMT at home, it’s important not to use/ingest gelatin capsules to transfer the stool into the colon. These capsules can dissolve in the stomach or small intestine, rather than just in the colon, causing problems like small intestine bacterial overgrowth (SIBO) and other digestive issues.
Researches do not know all of the adverse effects, but some may also include bacterial blood infections, fever, and exacerbation of IBD.
It is common to experience some mild side effects immediately after the treatment like abdominal discomfort, bloating, gas, diarrhea, constipation, vomiting, and transient fever (15). These symptoms tend to resolve on their own after a few days.
The long-term impact of FMT is not known, nor is its effect to manage more complex health conditions. Current literature seems to support its safety when administered properly, especially for managing C. difficile infection (16).
Summary: Serious risks are associated with FMT especially if the stool sample is not properly screened. Also, most experience mild gastrointestinal side effects immediately after the procedure, that resolve in a few days.
Should You Try This Excrement Experiment?
Fecal Microbiota Transplants (FMT) are a fairly simple procedure with promising results for a range of different health conditions.
Those with C. difficile infection should consider FMT as it has a 90% success rate after one treatment. However, other conditions like IBD, IBS, metabolic syndrome, ASD, etc. are still in experimental phases. Results vary and all of the risks are not completely known.
Doing FMT at home comes at your own risk. Properly screen the stool sample for any potential infection that can pass along. Also, knowing the stool donor’s health history (e.g. obesity, insulin resistance, allergies, etc.) can help you understand the health of the sample as well.
You may be better off finding a local clinical trial if you would like to explore the potential benefits of FMT. While this procedure is relatively safe, it can be a bit messy… and stinky.