The digestive system depends on beneficial bacteria to absorb nutrients and digest food efficiently, but some medical conditions and antibiotics can destroy these good bacteria. A fecal transplant is one way to reintroduce them.
Other names for a fecal transplant include bacteriotherapy and fecal microbiota transplantation (FMT).
In this article, learn how fecal transplants work and which conditions they can treat. We also cover the possible risks of this procedure.
What is a fecal transplant?
Fecal transplants can help to treat a range of conditions.
A fecal transplant from a healthy donor encourages the recipient's body to grow healthful bacteria, which can cure some infections and reduce the severity of certain gut health problems.
The gut is home to a delicate balance of millions of bacteria. When these bacteria become unbalanced, a person can develop diarrhea and other intestinal problems.
In some cases, the antibiotics that treat infections in the gut also kill off helpful bacteria. For example, about 20% of people who take antibiotics for Clostridium difficile, a common bacterial stomach infection that causes diarrhea, develop the condition again. This recurrence may be due to the antibiotics disrupting the gut microbiome, in which case, reintroducing good bacteria using a fecal transplant may help.
A doctor will carefully screen fecal transplant donors to ensure that their gut and feces are healthy. They will test them for various diseases, such as hepatitis.
In most cases, a doctor will deliver the donor feces to the recipient through a colonoscope. A colonoscope is a small, flexible tube that they can insert into the colon through the rectum. People usually take sedative drugs before the procedure, so they will not feel any pain or discomfort.
Another approach involves injecting liquid feces via an enema rather than using a colonoscope.
Fecal transplants originated in ancient Chinese medicine more than 1,700 years ago. In the past, this procedure involved drinking a liquid suspension of another person's feces — a highly risky technique. Today's fecal transplants are sterile and safe, and there is a growing body of research to support their use.
People with IBD may benefit from fecal transplants.
Research consistently finds that fecal transplants are highly effective in treating this dangerous condition.
In a small-scale 2014 trial, 70% of the participants had no symptoms after one fecal transplant treatment. The overall cure rate was 90% among those who underwent multiple treatments. The participants also had fewer bowel movements and ranked their overall health more highly following treatment. Other studies have reported similar success rates.
Doctors may also recommend fecal transplants to manage other gastrointestinal conditions. For instance, problems with gut bacteria may cause or worsen inflammatory bowel disease (IBD).
Researchers have found that fecal transplants may help treat IBD, though their effectiveness varies among studies. A 2016 review found that success rates in trials ranged from 36.2% to 77.8%, pointing to a need for further research.
Fecal transplants may also help with irritable bowel syndrome (IBS), a poorly understood condition that causes a wide range of digestive problems.
Research on fecal transplants for this condition is still in its infancy, but the authors of the above review noted that in a study involving 13 people with IBS, a fecal transplant resolved symptoms in 70% of the participants.
Fecal transplant research
Research on the wider effects of gut bacteria is still developing, but if gut health does affect overall health, fecal transplants could eventually treat a variety of conditions.
The authors of a 2016 review suggested that fecal transplants may eventually treat conditions such as:
- chronic fatigue syndrome
- mood disorders, such as depression
- nonalcoholic fatty liver disease
- hay fever
Risks and considerations
Taking antibiotics can increase the risk of complications after a fecal transplant.
Most studies suggest that fecal transplants are safe, especially when the sample comes from a healthy, thoroughly vetted donor.
However, doctors know less about the long-term safety of fecal transplants. As of 2019, a clinical trial is still assessing the long-term safety of fecal transplants via enema.
Feces can transmit diseases, but there are no known cases of feces from a healthy, vetted donor transmitting an infectious disease.
Taking antibiotics after a fecal transplant may cause complications, so it is important to tell the doctor about any current medications and antibiotics. Likewise, a person should mention a recent fecal transplant if they are receiving antibiotics for an infection.
Although research has shown fecal transplants to be safe, many people feel anxious about the procedure.
Some worry that it is unsafe or dirty to transplant someone else's feces into their body. However, people with chronic or life-threatening medical conditions may find that they can overlook the "yuck" factor.
A 2016 study identified several risk factors for fecal transplant failure, including:
- being female
- previous hospitalization
- recent surgery before the transplant
It can be difficult to access fecal transplants, especially for conditions other than CDAD.
Some people and a handful of natural health advocates suggest performing home fecal transplants by taking a pill or enema of feces from a healthy donor. However, no research supports doing fecal transplants at home, and there is no evidence that it is safe.
Without proper screening, a donor could transmit serious and potentially lethal diseases.
The idea of accepting feces from a healthy donor might seem peculiar, but the science supporting fecal transplants is becoming increasingly mainstream.
When other treatments fail, this innovative procedure may naturally restore the gut's health, allowing beneficial bacteria to grow, fight infection, and improve a person's health.
Not all doctors are knowledgeable about fecal transplants, so it is important to see an expert with sufficient experience of performing this procedure.