Aroniadis OC, et al. - Researchers conducted this double-blind, randomized, placebo-controlled crossover trial to evaluate the effectiveness of fecal microbiota transplantation (FMT) in alleviating diarrhea-predominant irritable bowel syndrome (IBS-D). Study participants included patients (aged 18 to 65 years) with moderate-to-severe IBS-D defined by an IBS-Symptom Severity Score of more than 175, recruited from three US centers. For this investigation, subjects got either 75 FMT capsules (each capsule contained approximately 0·38 g of minimally processed donor stool) or 75 placebo capsules over 3 days (25 capsules per day). Forty-eight patients were randomly assigned to receive FMT first (n=25) or placebo first (n=23) from May 28, 2015, to April 21, 2017. They concluded that FMT was safe, but at 12 weeks it did not induce symptom relief vs placebo. Abdominal pain, nausea, and exacerbation of diarrhea were the most common drug-related adverse events.