The therapy, Rebyota, is the first fecal transplant product approved in the United States, the FDA said in a statement. It’s cleared to combat Clostridioides difficile, or C. difficile, a bacteria that can flourish in the gut and cause diarrhea, abdominal pain, and fever, and in rare cases leads to organ failure and death. “Recurrent Clostridioides difficile infection impacts an individual’s quality of life and can also potentially be life-threatening,” said Peter Marks, MD, PhD, the director of the FDA’s Center for Biologics Evaluation and Research, in a statement. The approval of Rebyota “represents an important milestone, as it provides an additional approved option to prevent recurrent Clostridioides difficile infection.” Most cases of C. difficile develop when people take antibiotics, according to the U.S. Centers for Disease Control and Prevention (CDC). While this type of bacteria typically isn’t a superbug that resists treatment to antibiotics, it frequently develops and resurfaces repeatedly when people have other types of antibiotic-resistant infections that require multiple courses of treatment. This happens because antibiotics can alter the balance of microorganisms in the gut, known as the “gut microbiome,” in ways that make it easier for C. difficile to multiply and release toxins that cause diarrhea and other serious complications, according to the FDA. One of the risk factors for C. difficile is a history of these infections, the FDA said. Other risk factors include advanced age (older than 65) or a weakened immune system. After people recover from C. difficile infection it often returns more than once. Each additional recurrence makes repeat infection more likely, the FDA said, and treatment options are limited for these cases. Rebyota, consisting of rectally administered donor stool samples, is designed to help rebalance the microorganisms in the gut so that the microbiome becomes inhospitable to C. difficile. In clinical trials, the most common side effects of Rebyota were abdominal pain, diarrhea, abdominal bloating, gas, and nausea, the FDA said. Among adults who received at least one administration of Rebyota, about 71 percent of patients went eight weeks without a recurrent C. difficile infection, compared with about 58 percent of patients who got a placebo.