In the U.S., Clostridium difficile causes a quarter million hospitalizations and kills 14,000 people a year. These severe-diarrhea-causing bacteria resist treatment in many patients, and the rest of the time, the antibiotics kill off normal gut microbes that help keep pathologic species in check. Doctors have increasingly turned to a procedure called “fecal microbiotia transplantation” (FMT), which delivers fresh fecal material to help restore the normal balance of beneficial microbes.
These fecal transplants are about 90 percent successful, but they typically require invasive and uncomfortable colonoscopies or nasogastric tubes, which run from the nose down to the stomach. "Just getting the tube down is a problem," Elizabeth Hohmann of Massachusetts General Hospital tells NPR. And what if people gag and vomit? Would they inhale fecal matter? "That's pretty scary,” she adds.
Now it looks like frozen poop pills may be just as effective, according to results from a small pilot study published this week in the Journal of the American Medical Association.
Previous work has shown that frozen material works just as well as the fresh stuff, plus it means donors can be recruited and screened whenever, rather than when a recipient is in dire need. A bank of frozen samples can be prescreened for health issues (such as hepatitis) to reduce the risks of transmitting new infections.
To investigate the safety of simple oral capsules, Hohmann, together with Ilan Youngster from Boston Children’s Hospital and colleagues, enrolled 20 patients, ages 11 to 89, who’ve had at least two to three episodes of C. difficile infection. Some have had to be hospitalized, some haven't improve with traditional treatments. Stool samples were taken from healthy volunteers, then filtered, diluted, screened, and placed into capsules, which were stored at minus 80 degrees Celsius for four weeks.
The patients took 15 capsules a day for two consecutive days. About the size of a large vitamin, these 1.6-gram capsules are designed to open when they reach the small intestine. (Unfortunately, acid-resistant capsules are clear, but if you take it out of the freezer and swallow it really fast, the frost might help obscure the contents.)
"The use of capsules simplifies the procedure immensely, potentially making it accessible to a greater population," Youngster says in a news release. The symptoms were completely cleared in 14 recruits after a single treatment, without any recurrences. It took about four days for the pills to work. The other six patients received a second treatment about a week after the first, and the symptoms were then resolved in five of them -- though one patient’s infection did come back during the eight-week follow-up.
The overall success rate for the frozen capsules was 90 percent -- making them just as safe and effective as traditional fecal transplant techniques. “It’s probably not the best experience of your life,” Youngster tells Science. “But it beats getting a tube stuck down your throat or a colonoscopy… or having C. diff.”