Figure 2.

Short-term ABX changes cecal weight and fecal microbiota profile in male and female APPPS1-21 mice at 9 wk of age. (A) Cecal weights from vehicle- or ABX-treated male and female mice. ABX resulted in cecal enlargement in both sexes. One-way ANOVA: F(4, 45) = 11.02, P < 0.0001. Sidak post hoc analysis showed significantly larger cecal size in ABX-treated male (0.534 ± 0.041) and ABX-treated female (0.388 ± 0.021) mice compared with their vehicle-treated counterparts (M_Ctr = 0.406 ± 0.019, F_Ctr = 0.292 ± 0.0113; P = 0.004, P = 0.013, respectively). FMT treatment in ABX-treated male mice restored cecal weights (0.420 ± 0.028), similar to vehicle-treated male mice (0.406 ± 0.019; P = 0.992). (B and C) The α-diversity was measured by using observed index (B) and Shannon index (C). Observed index showed reduced diversity in ABX-treated male and ABX-treated female mice compared with their vehicle-treated counterparts (Kruskal-Wallis: P = 0.03, P = 0.01, respectively). Shannon index comparison showed no significant differences between groups (P > 0.05). (D) PCoA plot generated using unweighted version of the UniFrac distance metric. The two components explained 30.2% of the variance. ABX treatment of male and female mice resulted in separate clusters at the time of sacrifice. (E) Log₂ fold change of taxa presentation from ANCOM comparison of 16S profile of fecal microbiota. ABX treatment resulted in sex-specific taxa changes. Observe the flat line for comparison between groups M_Ctr and M_Abx+FMT and M_Ctr and F_Ctr, suggesting no major changes between these groups. M_Ctr = vehicle-treated male, M_Abx = ABX-treated (PND14–PND21) male, M_Abx+FMT = ABX-treated (PND14–PND21) male followed by FMT (PND24–PND63) from age-matched Tg-donor male, F_Ctr = vehicle-treated female, and F_Abx = ABX-treated (PND14–PND21) female. n = 9 or 10 mice per group. Data are mean ± SEM. *, P < 0.05; **, P < 0.01. PCoA, principal coordinate analysis.