LoricaLady
I do not have an autistic child but a friend's child was recently diagnosed with it so I have been particularly interested in research on this.
I listened to the material in the vid below and it sounded credible to me, personally. Dr. Campbell says her own son was diagnosed with severe autism and is now normal. She mentions fungal infections (such as candida I assume) that can result from lack of good bacteria in the gut.
Some consider the autism diet & probiotic appraoch to also be very helpful with A.D.D. and things like schizophenia & depression.
There is also an article in Nature Magazine talking about apparent connections between gut flora & autism.
For whatever it is worth (I have no way to know for sure) I am including these links just in case it might help someone:
http://www.youtube.com/watch?v=GjJhh47Emao
http://www.youtube.com/watch?v=nLP0Ijo2CK4