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Editorials
Figure 1. Fecal microbiota transplant (FMT) as a potential decolonization strategy for multi-drug resistant organisms (MDRO) in hematologic malignancy patients.
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After cytotoxic chemotherapy, hematopoietic stem cell transplantation (HSCT), and antibiotic administration, the likelihood that resistant bacteria replace diverse microbiota increases. FMT can potentially restore susceptibility to antimicrobials by replacing resistant bacteria with a diverse microflora when used as a decoloniza- tion strategy in response to infection or colonization with MDRO. When administered prior to cancer treatment, FMT may potentially mitigate dysbiosis and selection of resistance.
ed donors was preferred as it was perceived that common environmental exposures would reduce additional risk of transferring infectious agents between the donor and recipient. Intriguingly, neither of the two cases using an unrelated donor was successfully decolonized; given so few numbers, we cannot determine if this result is signif- icant. Consequently, the best choice of donor remains to be explored. If it were to be found that related donors are in fact preferable to universal donors, appropriate screen- ing and regulations will be an important consideration in the future.
One critical piece missing from this study is the under- standing of the microbiome in this process. Although the- oretically FMT decolonization works via restoration of microbial diversity leading to colonization resistance and displacement of the MDRO,12,13 experimentally showing what micro-organisms were important for decolonization in each case, which organisms presented robust and durable colonization, as well as if resistance genes were completely displaced after FMT would strengthen these types of studies and vastly improve the understanding of the mechanism by which FMT decolonizes MDRO. This represents an important future opportunity for investiga- tors.
With MDR infections set to be the world’s leading cause of morbidity and mortality by the year 2050, set to
surpass even cancer, and with few new antimicrobials in the pipeline, the need for novel and different approaches to treat MDR infections is critical.14 Moreover, we need to improve our clinical understanding of the antibiotic resis- tome, particularly in immunocompromised patients who experience repeated exposures to antimicrobials. Although no large randomized controlled trials have been performed to study the efficacy and safety of FMT for MDR organisms in the immunocompromised patient, this study and others have provided some promising evi- dence, and suggest that a non-antibiotic therapy for MDR colonization and infections may become common prac- tice in the future for patients with hematologic malignan- cies.15-17 The use of FMT as a decolonization agent both as a prophylactic and treatment measure may prove effec- tive in preventing MDR outbreaks and transmission, pro- longed in-hospital care, recurrent infection, and improve the overall outcomes of HSCT patients. Given the numer- ous potential benefits, and demonstrated safety and effi- cacy, the fear and negative perception of FMT in the can- cer setting is unjustified.15
Acknowledgments
JGP is supported by the NIH (K01 AI143881). RRJ is sup- ported by the NIH (R01 HL124112) and the Cancer Prevention and Research Institute of Texas (RR160089).
haematologica | 2019; 104(8)