'Poop Transplants' Can Transmit Deadly Superbugs, FDA Warns

The bacteria Acinetobacter baumannii can be a hospital-acquired infection
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"Poop transplants" have shown promise in treating severe diarrhea, but now, the Food and Drug Administration (FDA) is warning that these transplants may risk spreading superbugs.

On Thursday (June 13), the FDA announced that two people who underwent this procedure, known medically as fecal microbiota transplantation (FMT), contracted serious drug-resistant infections and one of those patients died.

The two patients, who had weakened immune systems, received fecal transplants from the same donor. Afterward, both patients developed an infection with a strain of Escherichia coli bacteria that's resistant to multiple types of antibiotics. [The Poop on Pooping: 5 Misconceptions Explained]

The donor's stool hadn't been tested for this type of bacteria prior to the transplants. After the two transplant recipients developed infections, the donor stool was tested and found to be positive for the same drug-resistant bacteria seen in the patients.

FMT is considered an experimental treatment for Clostridium difficile, a bacterial infection that causes severe diarrhea and can be life-threatening. The procedure aims to restore a better balance of bacteria within the gut. It involves taking fecal matter from a healthy donor and delivering it into a patient's colon, either directly, through an enema or other infusion of stool, or with the use of "poop pills," capsules containing fecal matter that patients take by mouth.

"While we support this area of scientific discovery, it's important to note that FMT does not come without risk," Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said in a statement. "We've become aware of infections with multidrug-resistant organisms after patients received investigational FMT, including one patient death. We therefore want to alert all health care professionals who administer FMT about this potential serious risk so they can inform their patients."

The FDA will now require screening of donor stool for multidrug-resistant organisms before the stool's use in any FMT procedure. Potential FMT donors will also be asked questions to determine if they may be at risk for carrying such drug-resistant bacteria, and they will be excluded from donating if they have certain risk factors.

The FDA warning "underscores the importance of why new therapies are thoroughly studied to ensure [that] the benefits of taking them outweigh the risks to patients, and we will continue to aggressively monitor clinical trials [of FMT] to ensure patients are protected when safety concerns arise," Marks said.

Originally published on Live Science.

Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.