Scientists continue to hunt for safe ways to ease the day-to-day challenges faced by children with autism spectrum disorder and attention-deficit/hyperactivity disorder. A new randomized, placebo-controlled trial published in Research on Child and Adolescent Psychopathology reports that a 12-week course of two probiotic strains was linked to lower hyperactivity-impulsivity ratings in children aged five to nine and to modest gains in comfort-related quality-of-life scores among children with autism.