FMT: Is it here to stay after new therapies become available?
The first time I heard about “stool transplant” was in the late 1990s when I was attending a regional winter meeting of gastroenterologists in Brainerd, Minnesota (ironically, the site of an unexplained but well-documented outbreak of chronic diarrhea in the 80s).
A gastroenterologist from Duluth gave a presentation at the meeting about his experience with administering feces via nasogastric tube to treat patients experiencing recurrent Clostridioides difficile infections. Reactions ranged from “interesting but doesn’t apply to my practice” to “that crazy Norwegian is at it again.” These intrepid docs from Lake Superior ultimately had the last laugh when they published their experience in a major infectious diseases journal.
Fast forward to the early 2010s. I had several IBD patients who were plagued with recurrent C. difficile, with one of them experiencing 13 documented recurrences. I would send these patients to Alexander Khoruts, MD, in Minneapolis for fecal transplant, and the results were amazingly positive. My colleague, Sahil Khanna, MD, began a fecal microbial transplant program at Mayo Clinic 9 years ago. Since then, over 1,000 patients here have received fecal microbiota transplantation (Khanna, personal communication). FMT has become a well-established therapy for recurrent C. difficile infection in the United States.
As well outlined this month’s cover story, it seems that the confluence of two different events may markedly reduce the availability of and perhaps the need for FMT in the future. First, the COVID-19 pandemic has markedly impacted the ability to acquire donor stool. Secondly, the “gray” regulatory status of FMT in the United States means that as microbial-based therapies are formally approved for treatment of recurrent C. difficile, FMT could lose its place in the treatment algorithm.
The first obstacle seems to be surmountable. FMT programs with their own fecal donor supply have implemented regimens of testing for SARS-CoV-2, and these appear to be successful at eliminating or markedly reducing the chance that FMT recipients will develop COVID-19. The changes described in the cover story may mean that centers that perform FMT but outsource their stool supply to OpenBiome will have to acquire their own donor stool supply.
The second impediment may be more challenging. FMT is a “blunt hammer,” and there may be unintended consequences such as acquisition of and infection with multi-drug resistant organisms. Standardized “pharmaceutical grade” microbe-derived therapies are in the works, and several of these agents have phase 3 trial data that appear promising (albeit not fully published at this point). Therefore, it’s possible that by next year there will be commercially available microbial-derived products for this vexing problem. Hopefully, FMT may remain a “fallback” option for patients who cannot get the new therapies due to insurance, cost and/or access issues.
- Aas J, et al. Clin Infect Dis. 2003;doi:10.1086/367657.
- Khanna S, et al. Am J Gastroenterol. 2020;doi:10.14309/ajg.0000000000000689.
- Khanna S, et al. Mayo Clin Proc. 2021;10.1016/j.mayocp.2021.04.005.
- Khanna S. J Intern Med. 2021;doi:10.1111/joim.13290.
- Osterholm MT, et al. JAMA. 1986;doi:10.1001/jama.1986.03380040058029.