Following the FDA's safety alert last week regarding the use of fecal microbiota for transplantation (FMT), the Microbiome Therapeutics Innovation Group said its members are working with the agency to develop guidelines for applying drug development and safety criteria related to microbiota-based therapeutics. In the safety alert, the FDA stressed the importance of testing donor stool for multidrug-resistant organisms. It reported that two immunocompromised adults developed invasive infections caused by extended-spectrum beta-lactamase-producing E. coli after they had received investigational FMT. One of the patients died.