APP and Alzheimer disease: Transgenic animal models of AD such as the double transgenic mice expressing a chimeric mouse/human amyloid precursor protein (Mo/HuAPP695swe) and a mutant human presenilin 1 (PS1-dE9) (APP/PS1) mice, have dysbiosis, with increased relative abundance of B. subtilis (Bacillus subtilis) and E. coli (Escherichia coli) (Harach et al., 2017), large producers of Aβ.