Fecal microbiota transplants (FMTs) are exactly what they sound like. They involve taking feces from a healthy person and putting them into the body of a sick patient to strengthen the community of bacteria that live in the patient's gut.
FMTs are very effective at curing stubborn infections with Clostridium difficile (C. diff). The deadly bacteria cause 500,000 illnesses and 14,000 deaths each year in the United States. Small studies have shown that FMTs can cure about 90 percent of serious C. diff infections. They have been so successful that scientists are testing the transplants for other conditions, such as irritable bowel syndrome.
However, FMTs have their downsides. They’re invasive, they can spread disease, and — let's face it — they're gross.
What if patients could get the benefits of an FMT without the “ick factor”? A team led by researchers at the Mayo Clinic has developed a delayed-release pill, dubbed SER-109. Research suggests that it may be just as effective as a traditional transplant.
How Does the Pill Work?
In a trial of 15 patients with multiple flare-ups of C. diff infection, SER-109 cured all 15 within eight weeks. At the end of the trial, none of the patients had diarrhea, the hallmark of C. diff infection. All tested negative for the bacteria.
“The results of the study were not surprising and we were expecting a high cure rate,” lead study author Dr. Sahil Khanna of the Mayo Clinic told Healthline. “Previous studies involving conventional fecal transplant from the upper gut have demonstrated good success rates.”
Doctors think that giving patients large doses of antibiotics triggers C. diff infections. Antibiotics destroy the normal, helpful gut bacteria that help the body fight harmful microbes like C. diff. To cure the infection, doctors must reintroduce the good bacteria the patient has lost.
The pill required far fewer live bacteria than a traditional transplant. Even with fewer bacteria to re-seed the patients' guts, the researchers confirmed that the pill quickly restored bacterial diversity.
Khanna, a gastroenterologist, said that the delayed-release capsules allowed the bacteria to survive the acidity and enzymes in the upper gastrointestinal tract and make it into the patient's lower gut.
The Rise of 'Ecobiotics'
Khanna calls SER-109 an “Ecobiotic,” as opposed to a “probiotic” (the kind you might find in the yogurt aisle of a supermarket).
“Ecobiotic products are combinations of a small number of selected discrete organisms that work by enabling a shift from a disease state to one of health. Ecobiotics are designed to rapidly, safely, and potently … target important diseases by positively reshaping the microbiome,” Khanna said.
“The first step is to collect human data about the biology of the microbiome covering organisms, their biology, and their environment in both disease settings and those of health,” Khanna added. “Through a set of algorithms, it is determined which organisms, if added in concert, can most effectively engage with the microbiome of disease and shift it to one of health.”
Probiotics, on the other hand, contain just one or a few strains of bacteria that doctors think might offer health benefits in high enough doses.
What does Khanna recommend to people who want to keep their gut microbiomes healthy?
“There are several known modifiable factors that may adversely affect the microbiome,” Khanna said. “However, what comprises a healthy microbiome is not completely understood. It would be plausible to suggest that avoiding unnecessary antibiotics, smoking cessation, routine exercise, and weight loss are all possible interventions, which will increase the likelihood of maintaining a healthy microbiome.”
Photo courtesy of CDC/Lois S. Wiggs.