Fecal microbiota transplants (FMT) pose a risk of serious or life-threatening adverse events likely because of transmission of pathogenic organisms, the US Food and Drug Administration (FDA) warns in a new safety communication.

The FDA said it is aware of infections caused by enteropathogenic Escherichia coli (EPEC) and Shigatoxin-producing Escherichia coli (STEC) that occurred following FMT. The agency suspects the infections are a result of transmission of these pathogenic organisms from FMT product supplied by US stool bank company OpenBiome.

The company provides FMT product manufactured from pre-screened donors to healthcare providers and researchers.

In a statement on its website, OpenBiome said it was "immediately" implementing changes to the screening program in collaboration with FDA to ensure all FMT material is appropriately screened for these pathogens.

FMT-Related Infections, Two Deaths

The FDA safety alert describes six patients who received the company’s FMT product for Clostridium difficile infection unresponsive to standard therapies and who developed infections caused by EPEC (two patients) or STEC (four patients). Four patients required hospitalization.

The two patients who developed EPEC infection received FMT product prepared from two different donors' stool. All four STEC infections were tied to stool prepared from a single donor.

OpenBiome also notified the FDA that two patients died after receiving the FMT product that was prepared from the same donor associated with the STEC infections. The deceased patients had underlying chronic medical conditions and received FMT for C difficile infection. The patients both developed diarrhea following FMT, but were not tested for STEC.

The deaths occurred before the four patients with the STEC infections were reported to either OpenBiome or the FDA. The agency notes that it is not known if STEC infection contributed to the deaths.

In the safety alert, the FDA recommends that patients considering FMT for the treatment of C difficile infection should speak with their treating clinician and understand the associated risks.

The recommendation is in line with FDA guidance issued in July 2013, which requires physicians to obtain adequate informed consent. The consent, the agency says, should include a statement that the use of FMT to treat C difficile is investigational, and that physicians discuss potential risks with patients.

Adverse events or side effects related to the use of FMT products should be reported to the FDA's MedWatch Safety Information and Adverse Event Reporting Program.

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