FIGURE 2.

Schematic diagram showing details of the microbiota-gut-hippocampus axis at different levels. The normal gut microbiota enhances synaptic plasticity and, thus, hippocampal-dependent learning and memory, through a balance of anti-inflammatory/inflammatory and antioxidant/oxidant agents, stimulatory/inhibitory synaptic transmission, as well as enhancement of intracellular devices. While intestinal microbiota negatively affect biochemistry, immunology, neurochemistry and intracellular cascades of synaptic plasticity and cognition, probiotic treatment restores dysbiotic hippocampal disorders. Anti-inflamm. Fac., anti-inflammatory factors; Proinflamm. Fac., proinflammatory factors; Antioxid. Fac., antioxidant factors, Oxid. Fac., oxidant factors; Excit, excitatory, Inhib., inhibitory.