Short-term benefit from oral vancomycin treatment of regressive-onset autism

In most cases symptoms of autism begin in early infancy. However, a subset of children appears to develop normally until a clear deterioration is obse rved. Many parents of children with "regressive"-onset autism have noted an tecedent antibiotic exposure followed by chronic diarrhea. We speculated th at, in a subgroup of children, disruption of indigenous gut flora might pro mote colonization by one or more neurotoxin-producing bacteria, contributin g, at least in part, to their autistic symptomatology To help test this hyp othesis, II children with regressive-onset autism were recruited for an int ervention trial using a minimally absorbed oral antibiotic. Entry criteria included antecedent broad-spectrum antimicrobial exposure followed by chron ic persistent diarrhea, deterioration of previously acquired skills, and th en autistic features. Short-term improvement was noted using multiple pre- and post-therapy evaluations. These included coded, paired videotapes score d by a clinical psychologist blinded to treatment status; these noted impro vement in 8 of 10 children studied. Unfortunately, these gains had largely waned at follow-up. Although the protocol used is not suggested as useful t herapy, these results indicate that a possible gut flora-brain connection w arrants further investigation, as it might lead to greater pathophysiologic insight and meaningful prevention or treatment in a subset of children wit h autism.