What are the parasites and bacterias usually in the gut? can they be associated with autism?

Intestinal bacteria,: yeast or parasites don't. cause Autistic Spectrum Disorder. Chromosomal Microarray testing has found over 100 copy repeat errors, fewer or more than 1 copy of a small gene sequence from either parent that increase susceptibility to ASD. Epigenetic factors that alter function , but not structure or sequence of fetal genes, like low folate (folic acid) levels at conception, alcohol & the flu also increase risk