The diets that contain bacterial lipopolysaccharides change cell membranes and delay the clearance of mycotoxins such as patulin and ochratoxin A that enter the brain and lead to neuron apoptosis.
There is a recent paper showing evidence that LPS enters the brain. But traditionally it was Prostaglandins that were believed to mediate the effect of LPS in peritoneum. (I am not sure about processing via diet though).