Probiotics were shown to reduce CNS inflammatory processes and activation of microglia, decreasing neuroinflammation, probably through the production of the brain-derived neurotrophic factor (BDNF) and the improved synaptic plasticity, related to an increased concentration of postsynaptic density protein 95 (PsD95) [53] A randomized, double-blind, and controlled clinical trial on AD patients showed that a 12-week probiotic treatment induced a significant improvement in the MMSE score and a significant decrease in plasma malondialdehyde in the probiotic-treated group [54]. This evidence concerns the gene BDNF and Alzheimer disease.