Hi Jim, 
One very revealing study was done (I think it was in 2004) on autistic children who showed normal development for the first year or two then regressed into autism. I can't put my hands on the study right now but they used an antibiotic that is usually only used for antibiotic resistant infections. The children all normalized for a brief period (several weeks I think) then regressed again.  The working hypothesis was that they had abnormal bacteria growing in the gut. These abnormal bacteria produce a toxin that was getting into the bloodstream and traveling to the brain where it did its damage. The bacteria were able to survive the assault by the antibiotic and subsequently rebounded to their previous status leading to a return of the autism. 

This made sense to me because that would explain why a gluten free, dairy free diet would help but not reverse many cases of autism because it would reduce production of zonulin and maintain a better mucosal barrier in the gut. This would block some, but not all of the toxin produced by the abnormal bacteria. In any case, I think that the paper makes a pretty good case for causation of some cases of autism by the bacteria in question. 

I'm sorry I can't be more specific by identifying the bacterium, the toxin, and the drug in question. I looked quite extensively for the paper but could not find it.   

best wishes, 
Ron

-----Original Message-----
From: Paleolithic Eating Support List [mailto:[log in to unmask]] On Behalf Of [log in to unmask]
Sent: Tuesday, January 24, 2012 11:15 AM
To: [log in to unmask]
Subject: Re: Paleo gut flora

This is interesting info but are abnormal gut flora (or comprimised  
immune systems or vaccines or iodine deficiency or whatever) a *cause*  
of autism or is it merely correlated?

Man, if I could have one wish in this world it would be that people --  
especially scientists, for goodness sakes! -- to understand the  
difference between causation and correlation.

There.  I feel better.

Jim