When Anne Maldzinski underwent a blood stem-cell transplant to cure her cancer, the procedure triggered a life-threatening immune reaction that ravaged her intestines, leaving her survival dependent on a surprising treatment: human feces.

After multiple immune-suppressive drugs failed to control the symptoms of graft-versus-host disease — a common complication for donor bone marrow recipients — Maldzinski was given an experimental therapy developed by French biotech MaaT Pharma through an early access program. The effect was dramatic.

"After weeks of having terrible diarrhea, I was much better the next day,” Maldzinski recalled of the enema treatment she received while in intensive care at a hospital in Nice, France, in November 2021.