Overall Diagram for Hypothesized PPA Effect on hNSC in vitro. During the early stages of pregnancy, increased consumption of PPA-rich processed foods combined with pre-existent dysbiosis may lead to accumulation of PPA in the maternal GI, travel through general circulation, cross the placental barrier, and interfere with neural differentiation through binding to GPR41 receptor preferably expressed on glial progenitor cells. This will activate a downstream molecular pathway resulting in PTEN inhibition and activation of pro-survival Akt pathway, therefore favoring glial progenitor cells proliferation and differentiation. Mature glial cells will move on to produce inflammatory cytokines and release GFAP, all of which mimic gliosis and neuro-inflammation observed in ASD. Some illustrations used in this figure were originated from leased Motifolio (Scientific Illustration Toolkits for Presentations and Publications) materials.