Late-onset autism has been increasingly diagnosed over the past two decades. Genetic susceptibility to autism has been extensively examined without yielding insight as to causation of autism. A microbial ecologic cause, either related to dysbiotic host flora or occult infection by neurotoxic intestinal microbes was postulated based on a common pattern of antibiotic exposure and syndrome onset.
In 2000 Dr. Sidney Finegold published a case series of suggesting a possible link with clostridial organism infection. In the past 5 years, incidental case referrals for fecal transplantation has shown that prior treatment with vancomycin ameliorates symptoms in some patients, and fecal transplantation averts the regression or partially ameliorates clinical findings for variable durations in children that are between 3-8 years age. Serial fecal sampling prior to antibiotic treatment, after attempted ablation of the intestinal microbiota with multiple antibiotic treatment with nitazoxanide, vancomycin, norfloxacin and nystatin (the latter 2 to prevent overgrowth of gamma proteobacteria and fungi, respectively), and after fecal transplantation, with quantitative total anaerobic cultures to recover the most numerically dominant clones and to subject these clones for sequencing identity suggests certain clostridial organisms are present in association with neurocognitive dysfunction.
It is proposed to study a cohort of newly diagnosed children with late onset autism aged 3-5 years of ages in an randomized placebo controlled clinical trial and to follow clinical and microbial end points in a collaborative study.