Sorry about the misleading thread title, but a more descriptive title was much too long.
Mice with autism-spectrum disorders (ASD) induced by maternal obesity and high-fat diet showed improvement in several areas, including social interactions and behavioural improvements, after eating the faeces of “normal” mice. Further study indicated that the bacterium Lactobacillus reuteri was largely responsible, and that the brains of ASD mice (caused by maternal high-fat diet) showed reduction of oxytocin immunoreceptive neurons in the paraventricular nuclei of the hypothalamus.
Microbial Reconstitution Reverses Maternal Diet-Induced Social and Synaptic Deficits in Offspring (full text available, and fascinating.)

