Science writer Emily Willingham has painstakenly and repeatedly debunked questionable assertions that autism is caused by (and, in a variant, "cured" by introducing) bacteria. She also debunks the dangerous myths behind current "research" that introduced worm eggs (with the subsequent hatching of actual worms) into Autistic children.
Autism, immunity, inflammation, and the New York Times
One thing to note about all these questionable studies is that they often come with the rhetoric of "leaky gut." Rather than using more scientific terminology, these studies posit a "gut" that leaks, and then blame the entire range of Autistic characteristics and traits on this supposed fault in the gut.
The hygiene hypothesis, when examined closely, does not contain even a kernel of fact. It is premised on nostalgia for the "good old days" when, presumably, we were somehow "germier," maybe because we were working on farms or getting dirt under our nails, or drinking unpasteurized milk (even though some people have a strong belief in a "milk causes autism" theory.)
Please read Willingham's excellent article before you jump on the bandwagon and feed bacteria, worm eggs, or whatnot to your kids or yourself.
A post by Autism Expert Paula C. Durbin-Westby is here:
Albert Einstein College "Treating" Autism with WORMS?