MAPT and Alzheimer disease: A growing body of human research has identified several bacterial species, including Borrelia burgdorferi, Chlamydia pneumonia, and Helicobacter pylori, as factors that may increase susceptibility to AD by promoting tau protein hyperphosphorylation, elevating pro-inflammatory bacteria such as Escherichia/Shigella, and reducing anti-inflammatory gut microorganisms such as Ruminococcus [75,76].