October 1, 2018Microbiology
Allogenic hematopoietic cell transplantation involves a donor -- often but not exclusively a family member -- who gives the recipient stem cells that re-establish bone marrow production of blood cells and immune function to combat cancer. Antibiotics are essential to prevent bacterial infections in stem cell recipients. However, antibiotics also destroy beneficial bacteria that enhance immune function and resistance to infection. The loss of beneficial bacteria increases the risk of certain life-threatening infectious diseases and graft-versus-host disease (GVHD).
According to an article published in Science Translational Medicine (26 September 2018), autologous fecal microbiota transplantation (auto-FMT) has been shown to be a safe and effective way to help replenish beneficial gut bacteria in cancer patients who require intense antibiotics during allogenic hematopoietic stem cell transplantation. In the study, patients who underwent the procedure were randomly assigned into two groups: one group received standard care and the other received auto-FMT. Results showed that auto-FMT resulted in the recovery of beneficial gut bacteria to near baseline levels within days, thus restoring patients' digestive, immune and other essential functions. With standard care, beneficial bacteria typically take many weeks to recover from antibiotic treatment, leaving patients at risk of other infectious diseases, including Clostridium difficile.
The study involved cancer patients who provided their own fecal sample, which was frozen and stored prior to their cell transplantation procedure. Weeks later, when physicians confirmed that the transplanted cells were growing, they assessed the status of the patients' beneficial gut bacteria. The first 25 patients who lacked known beneficial bacteria were enrolled into the study and randomly assigned to the different treatment groups: 14 received auto-FMT by enema and 11 received standard-of-care. Results showed that the patients who received auto-FMT consistently regained bacterial diversity, composition and function; recovery of beneficial bacteria in the 11 control patients was delayed.
The authors are continuing to monitor the study patients to determine if auto-FMT improves patient outcomes, such as the incidence and severity of bacterial, viral and fungal infections and the incidence and severity of GVHD. Whether FMT from a healthy donor would be as beneficial as the patient's own fecal sample at restoring beneficial bacteria remains to be studied.