Gretchen Ertl for The New York Times The treatment may sound appalling, but it works. Melissa Cabral contracted an infection after taking an antibiotic for dental work. "If I didn't do it," she said of the fecal transplant, "I don't know where I'd be now." The Shit Doctor Transplanting feces from a healthy person into the gut of one who is sick can quickly cure severe intestinal infections caused by a dangerous type of bacteria that antibiotics often cannot control. A new study finds that such transplants cured 15 of 16 people who had recurring infections with Clostridium difficile bacteria, whereas antibiotics cured only 3 of 13 and 4 of 13 patients in two comparison groups. The treatment appears to work by restoring the gutâ€™s normal balance of bacteria, which fight off C. difficile. The study is the first to compare the transplants with standard antibiotic therapy. The research, conducted in the Netherlands, was published Wednesday in The New England Journal of Medicine. Fecal transplants have been used sporadically for years as a last resort to fight this stubborn and debilitating infection, which kills 14,000 people a year in the United States. The infection is usually caused by antibiotics, which can predispose people to C. difficile by killing normal gut bacteria. If patients are then exposed to C. difficile, which is common in many hospitals, it can take hold. The usual treatment involves more antibiotics, but about 20 percent of patients relapse, and many of them suffer repeated attacks, with severe diarrhea, vomiting and fever. Researchers say that, worldwide, about 500 people with the infection have had fecal transplantation. It involves diluting stool with a liquid, like salt water, and then pumping it into the intestinal tract via an enema, a colonoscope or a tube run through the nose into the stomach or small intestine. Stool can contain hundreds or even thousands of types of bacteria, and researchers do not yet know which ones have the curative powers. So for now, feces must be used pretty much intact.