Of the 92 AD associated genes (96 minus the four housekeeping genes) evaluated in the P. gingivalis 12-weeks post infection, the key target genes with statistically significant changes of their expression were cyclin dependent kinase 5 regulatory subunit 1 (Cdk5r1, 0.15 logfold change, p = 0.05) and Interleukin 1 alpha, (IL1a, −0.10 log fold change, p = 0.012). This evidence concerns the gene IL1A and Alzheimer disease.