Olsen et al. found that lipopolysaccharide (LPS) from PG activated the PI3K/AKT pathway, increased glycogen synthase kinase-3β (GSK-3β) mRNA expression, and inhibited GSK3β [117], and the inhibition of GSK3β activation may delay the pathologic progression of periodontitis-induced AD [118]. This evidence concerns the gene AKT1 and Alzheimer disease.