Microbial links to Alzheimer’s disease

Alzheimer's disease (AD) is a common chronic neurodegenerative disease that is characterized by (1) plaques, (2) neuronal death, (3) hyperphosphorylation of tau proteins, and (4) memory deficits. Despite extensive research, the underlying cause of AD is not fully understood. Evidence that infectious pathogens may trigger AD has been documented for decades. There are notable correlations between microbes (including bacteria, viruses, and fungi) and AD pathologies. Although it is yet to be determined if pathogenic microbes are the causative agent or a contributing factor to AD, the role of infections in the pathogenesis of AD should not be ignored. Even though the pathogens may not cause AD, they may play a direct role in the triggering or exacerbation of AD progression. In this mini review, the current status of pathogens' role in AD etiology will be presented.