How Fecal Transplant Eases Tough Infection
Goal is an easier delivery method for treating C. difficile
How it does that remains unclear. But the process, which reportedly dates back to 4th-century China, has been available to American patients since the 1950s. By some estimates, the success rate exceeds 90 percent.
The problem: Fecal transplants are delivered either by colonoscopy, by a tube threaded through the stomach, or by enema -- all somewhat unpalatable therapies.
Although Canadian researchers last fall reported success with a pill form of fecal delivery, that method is not yet approved by the U.S. Food and Drug Administration for general use.
For Young's study, the researchers conducted a comparative DNA analysis of bacteria found in stool samples from 14 C. difficile patients at a clinic in Minnesota.
All had experienced recurrent infections, and all had completed an ineffective regimen of antibiotics.
The samples were collected before undergoing fecal transplantation, and again two to four weeks following treatment, the study authors noted.
In addition, stool samples taken from 10 of the patients were compared with samples taken from healthy donors.
The team found a wide range of bacterial environments across samples, with the closest similarities seen among those taken from healthy donors and treated patients.
Compared with untreated patients, treated patients had a reduced population of problematic "proteobacteria" and an increase of beneficial "firmicutes and bacteroidetes" bacteria, the investigators found.
The researchers also isolated 75 different pathways by which the bacterial environment post-transplantation waged a war of resistance against C. difficile.
"So clearly there's not one thing that stuck out," said Young. "And we don't yet know which of these pathways are important."
Although new insights have been gained, "we're going to have to drill down even further going forward," Young added.
Another expert welcomed the new findings.
This work is "very exciting," said Jeffrey Cirillo, a professor of microbial and molecular pathogenesis at the Texas A&M Health Science Center College of Medicine in Bryan, Texas.
"It is interesting that not only do the recipients recover more quickly from [fecal material] treatment, but they also have a more diverse population of bacteria present," Cirillo said.
These observations hold promise for development of new methods to prevent recurrent infections, Cirillo added.