The author, a parent of a child with autism, describes an n=1 case in which his child's autism symptoms dramatically and rapidly improved following administration of a common antibiotic. The author asserts that this finding is not unusual in the autism population and that, when combined with prior recent medical research, suggests that a link between autism and the microbiome in some children is not just plausible, but in fact likely for some meaningful percentage of cases. The author argues for increased funding for a more thorough examination of links between autism and the microbiome and poses a series of questions to be further examined in future research.