Frozen Feces is as Good as Fresh Transplants

Frozen fecal matter has been proven just as effective as fresh feces when treating people for C. difficile infections, according to a recent study.

Clostridium difficile bacteria can be very dangerous to humans, as they commonly infect and inflame the colon, causing nausea, severe diarrhea, abdominal pain, and fever, according to the U.S. Centers for Disease Control and Prevention (CDC). C. defficile infections cause an estimated 250,000 hospitalization in the United States each year, with 15,000 of those infections resulting in death.

Past research has shown that the unusual practice of transplanting fresh stool from an adequate donor can replace and regrow microbes necessary for the colon to fight off an infection. Studies have shown that these transplants tend to have a 90 percent or higher success rate. However, according to a Massachusetts General Hospital (MGH) press release, these transplants are costly and time consuming, as screening for potential fecal donors involves a difficult testing process.

Now, a pilot study published in Clinical Infectious Diseases shows that frozen feces works just as well for the transplant process as fresh feces, as the essential microbial can survive the freezing process and aid in protecting the transplant recipient's colon once thawed.

According to the study, 20 patients who had experienced three or more episodes of mild to moderate C. difficile infection for which traditional antibiotic treatment proved inadequate. All the participants involved in the study received fecal matter from healthy donors who had been screened weeks before. After being donated, the fecal matter was filtered, diluted, screened, and finally frozen -- stored for at least four weeks. This storage time gem doctors extra time to test the safety of the feces again.

Overall, after one to two transplant treatments, 18 of the 20 patients were successfully cured of their infection and displayed evidence that microbial levels in their colon had been normalized as a result of the process. One of the two patients who were not cured dropped out of the study early and did not receive a second treatment.

According to the researchers, the more than 90 percent success rate of these transplants with frozen fecal matter shows that fresh samples are not necessary for the procedure, opening up the possibility of fecal matter banks and extended testing time to ensure safety.

The study was published in Clinical Infectious Diseases, an Oxford Journals publication, on April 23.