MAPT and Alzheimer disease: Further studies need to be done to investigate the molecular mechanism by which DNA from some species of bacteria produce effect while others do not alter tau aggregation.The findings obtained in the present work indicate that DNA may play a previously overlooked role in the propagation of tau protein misfolding and AD pathogenesis, providing a new conceptual framework that positions the compromised blood brain and intestinal barriers as important sources of microbial DNA in the brain; indeed, altered gut permeability and disrupted BBB could precede AD development64.