Today, fecal microbiota transplants are well recognized for their effectiveness in fighting certain intestinal infections, including infection resistant to C. difficile.
Today, fecal microbiota transplants are well recognized for their effectiveness in fighting certain intestinal infections, including infection resistant to C. difficile. However, therapy is not widely practiced and many patients remain reluctant. Second, transplantation of fecal microbiota (TMF) involves certain risks such as blood infections and the transmission of drug-resistant bacteria. Finally, from the composition of the “product”, to the selection of donors, to manufacturing and then delivery practices, therapy remains poorly documented in the literature, and this for most of the diseases associated with the microbiome. These 2 documents, presented in the journal Cell Host & Microbe, highlight the potential of the therapy but call for better documentation of its good practices and its evidence in the treatment of different intestinal diseases.
“Clinical trials are essential to make it clear”
A proof of concept on paper: the many microbes that live in the intestine are also found in the stool and transplants of fecal microbiota appear as a possible way to treat dysbiosis, restore balance in the bacterial communities of the microbiota and to bring in good bacteria. TMF could thus with great probable benefits be considered in the treatment of ulcerative colitis and Crohn’s disease.
Few studies on its use beyond C. difficile infection: in the United States, if the FDA agency authorizes the use of TMF to treat Clostridioides difficile infections that do not respond to standard therapies, provided that the attending physician obtains the patient’s informed consent, researchers who wish to test therapy for other diseases or conditions must submit a request for authorization. Complex requests given the different possible preparations, from autologous stools to those of stool banks or even in the form of “poop pills”.
Little data on the optimal composition of the product: beyond the methods of collecting and preparing the “material”, little is known about the optimal characteristics of the product: it is not known which is the best bacterial composition for a specific result. The FDA is working to provide this data, particularly for “screening” for “super donors” and manufacturing quality controls. The authors therefore provide here an overview of the FDA regulations on the fecal microbiota for transplantation. They also provide details that contribute to patient safety and the viability of bacteria in the transplanted material. These details include
a reference list of pathogens to exclude donors at high risk of “contamination”;
instructions on manufacturing processes and controls, such as the use of anaerobic chambers during product preparation in order to preserve the “good” bacteria – which can be very sensitive to oxygen: given the lack of knowledge on optimal bacterial composition to treat a particular disease, the loss of these anaerobic organisms could have a negative impact on the effectiveness of TMF.
Controlled clinical trials vs placebo for the treatment of specific intestinal diseases therefore remain necessary to demonstrate the safety and efficacy of the transplant and to advance the composition of the transplanted materials. These clinical trials are essential for clear, conclude the researchers. And if according to these experts, health agencies like the FDA are committed and collaborating in these tests,
there is still a long way to go before we can truly exploit fecal transplantation in a targeted and safe manner.