APP and Alzheimer disease: Also, inflammatory or Aβ-associated bacteria such as Erysipelotrichaceae (Bäuerl et al., 2018; Ticinesi et al., 2019) and Proteobacteria (Nagpal et al., 2019; Ticinesi et al., 2019; Nagu et al., 2021) increased in APP/PS1 mice, which play key roles in the pathogenesis of AD.