So does yeast cause autism?

This finding may be just another consequence of the abnormally-functioning autistic immune system. However, early antibiotic use may actually be the triggering factor for children predisposed to autism. It has been hypothesized that the candida might aggravate a condition of gut permeability (the "leaky gut" syndrome) which might let the gluten and casein proteins into the bloodstream before they are broken down, so it may in part be responsible for autistic behaviors. Many parents of children with ADD/ADHD as well as those with autism report that treatment for candida does improve their children's behavior and concentration.