Fig. 3

APP overexpression does not affect gut microbiome diversity prior to amyloid onset. Analysis of gut microbiome from stool samples collected at 6 wk of age while half of each genotype was still receiving dox chow, focusing on the effect of genotype. A, B Graphs of observed OTUs (A) and Simpson index (B) reveal that genotype had no effect on α-diversity at this age. Both measures were similar across genotypes whether APP overexpression was active (in untreated Tg mice) or not (with dox suppression). C, D PCoA plots of weighted UniFrac distances indicate that genotype did not affect β-diversity in untreated (C) or dox-treated mice (D). E The relative abundance of bacterial taxa is similar between genotypes at 6 wk of age for both treatment conditions. Statistical testing: Kruskal–Wallis (A, B), PERMANOVA (C, D), and Mann–Whitney U (E). n = 5–7 mice/group. Red and blue = dox-treated Tg and WT, respectively; grey and white = untreated Tg and WT, respectively