While several decades of research have slowly been building a scientific case for the efficacy of fecal transplants as a treatment for a variety of conditions, there is still a lack of consensus over the best way to prepare and administer these fecal samples. A new Australian trial has revealed significant success in fecal transplants treating ulcerative colitis, pioneering a new stool processing technique suggested to enhance the therapeutic effect of the treatment.

A fecal microbial transplant (FMT) is not a particularly new medical concept. The idea can be traced back thousands of years in Chinese medicine, and arose in the West in the 1950s when a team of American surgeons began to experiment with the treatment. Over the last decade, however, interest in fecal transplantation has surged in Western medicine, alongside the frequent breakthroughs in gut microbiome research.

Ulcerative colitis, a form of inflammatory bowel disease, has long been a target for researchers experimenting with fecal transplantation. This latest study looked to develop a new processing technique for fecal samples in the hopes of making the treatment more effective.

The hypothesis behind the research was that because a great deal of colonic bacteria is oxygen sensitive, it is reasonable to assume general stool preparations for fecal transplants can destroy a variety of valuable organisms. So the researchers utilized an anaerobic processing technique to produce the samples administered in the trial.

"The most important difference in this trial compared to previous studies is the use of anaerobic (oxygen-free) stool processing," explains Sam Costello, study lead from the University of Adelaide. "Many gut bacteria die with exposure to oxygen and we know that with anaerobic stool processing a large number of donor bacteria survive so that they can be administered to the patient."

The trial involved 73 subjects with mild to moderate active ulcerative colitis. Participants were randomly, and blindly, split between a placebo group receiving their own stool samples, or the experimental group receiving healthy donor-derived stool that had been anaerobically processed. Only three doses were administered to each subject over a one-week period, with the first dose delivered via colonoscopy and the following two doses by enema.

The dosing duration tested in the trial was much smaller than many prior studies, but the hypothesis was that it could still be effective because a higher volume of beneficial bacteria would be present in each sample due to the anaerobic processing technique. The results certainly backed up the hypothesis, with the experimental group revealing a 32 percent remission rate after eight weeks compared to just a nine percent remission rate in the placebo group.

Questions still remain over the long-term efficacy of the treatment, with only about half of the successful subjects maintaining remission after 12 months. Further work is undoubtedly necessary to improve these long-term remission rates. A more prospective outcome proposed by the researchers is to commercialize the development of this kind of microbial-based therapeutic, ultimately transcending the need for general whole fecal sampling and donations.

"Our long-term aim is to develop rationally designed microbial therapies that can replace FMT,'' says Costello. "These will have bacteria in a pill that can carry out the therapeutic effect without the need to take whole feces."

The new research was published in the journal JAMA.