Fecal Microbiota Transplantation: The Case of Immunocompromised Patients

I read with great interest the review by Austin et al about fecal microbiota transplantation in the treatment of Clostridium difficile infections. They rightly point out that fecal microbiota transplantation is efficacious for patients with recurrent C. difficile infection, with an excellent short-term safety profile. However, I want to raise a safety concern for comment, that is, the case of immunocompromised patients not evoked by the authors.

Fecal microbiota transplantation has been used with special caution in patients with immunodeficiencies, either systemic or at the mucosal colonic barrier level (eg, inflammatory bowel disease), due to the theoretical potential for infection. Recent guidance issued by the Fecal Microbiota Transplantation working group specified that considerations for increased risk of adverse events should be given to patients on major immunosuppressive agents (including high-dose corticosteroids, antitumor necrosis factor agents, and others) and patients with decompensated liver cirrhosis, advanced acquired immune deficiency syndrome, recent bone marrow transplant, or other cause of severe immunodeficiency. Ironically, these patient categories are the ones who are at increased risk of developing recurrent or severe C. difficile infections; nevertheless, some of these have undergone fecal microbiota transplantation in different centers without major consequences. Similarly, while published guidelines recommend avoidance of fecal transplant in solid organ transplant recipients, successful C. difficile infection treatment with fecal microbiota transplantation has been reported in some of these recipients. In patients with inflammatory bowel disease and concomitant recurrent C. difficile infection, fecal microbiota transplantation safety has been debated due to its possible association with colitis flare, especially in ulcerative colitis. Yet, a systematic review on fecal microbiota transplantation in inflammatory bowel disease management showed C. difficile infection resolution in the small patient group (15 cases) treated for both diseases. Finally, it is worth noting that a recent report of a multicenter retrospective series of a limited number of immunocompromised adult (n = 75) and pediatric (n = 5) patients showed the effective use of fecal microbiota transplantation for recurrent, refractory, or severe C. difficile infections, with few adverse or serious adverse events and no related infectious complications, but also suggested that fecal microbiota transplantation, of which the risks may be greater in severely ill patients, should be cautiously considered in patients with significant comorbidities such as immunodeficiencies.