BGM dysbiosis with Abx treatment does not change the accumulation of total Tau (Tau499) and phosphorylated Tau (pTau) in the hippocampus at the early symptomatic stage of AD. Immunohistochemistry analysis for Tau499 and pTau. Mean Tau499 area ratio (±SEM) in (a) subiculum, (b) CA1, and (c) CA3 and mean pTau area ratio (±SEM) in (d). subiculum, (e) CA1, and (f) CA3 of F1 male non-transgenic (NoTg) or Alzheimer’s disease triple-transgenic (3xTg) mice that received water (Ctrl) or antibiotics (Abx) from gestation to PD150. The results were analyzed with a two-way ANOVA, * p < 0.05, ** p < 0.01 vs. NoTg; n = 4–5 mice per group.