Putative roles of gut-brain communications, gut microbiota and systemic inflammation in the dietary arachidonic acid effects on the sensitivity to the Aβ peptide oligomer neurotoxicity. ARA has an impact directly or indirectly on the brain. An ARA-rich diet can modify the composition of intestinal microbiota to induce inflammatory mediators and thus, have effects on the Aβ peptide oligomer neurotoxicity. Indeed, arachidonic acid can affect the brain by going liver, adipocytes and inflammatory mediators.