Fig. 1

Schematic of experimental design. A Transgenic APP/TTA (Tg) and wild-type (WT) mice were split into two groups: one group received dox chow from P3 until P42, the other group received standard chow. At 6 wk, a fecal sample was collected from all mice and dox chow was removed. At 12 wk, another fecal sample was collected from all mice. Following fecal sampling at 12 wk, WT mice were used for LPS injection. Additional WT mice were injected with saline at 12 wk as controls for LPS without prior microbiome sampling. All mice, Tg and WT, were harvested 18 h after injection of the WT mice. B Aβ immunostaining of Tg mice harvested at 12 wk. Mice treated with dox for 6 wk followed by 6 wk of transgene expression showed no evidence of amyloid pathology (left). Amyloid pathology was observed across the cortex and hippocampus in untreated mice that expressed transgenic APP from birth (right). Most plaques were fibrillar deposits and co-labeled for Aβ (red, inset) and thioflavin-S (green). Created with BioRender