Further research has shown that multiple factors are involved in the colonization of S. aureus on AD skin, including enhanced bacterial-keratinocyte adhesion, antimicrobial peptide deficiency, decreased levels of filaggrin and filaggrin degradation products, Th2/Th17 cytokines overexpression, microbiota dysbiosis, and altered lipid profiles (8). This evidence concerns the gene FLG and Alzheimer disease.