FIGURE 1.

Toxic effects of synthetic Aβ₄₂ on murine fecal microbial organisms. (A) Fecal samples of transgenic 5xFAD mice and wild type littermates were diluted and incubated with Aβ₄₂ peptide or scrambled control (2 μM) for 10 min. Viability was measured and calculated in percent of scrambled peptide treated samples (n = 13 animals per group,♂ = 6–7, ♀ = 6–7). (B) Fecal material suspension from wild type mice were incubated with 2 or 10 μM Aβ₄₂ or the respective amount of scrambled peptide. Subsequently, aliquots of further diluted bacteria suspension were plated on Schaedler agar and incubated anaerobically for 48 h at 37°C. Number of colony forming units (CFU) of samples treated with scrambled peptide control were set to 100% (n = 7 animals per group; ♂ = 3, ♀ = 4). (C, D) After incubation of fecal samples from transgenic or wild type mice with 2 μM Aβ₄₂ or scrambled peptide, suspensions were spread on plates selective for Lactobacillaceae (C) and Enterobacteriaceae (D) (n = 10–11 per group, ♂ = 5–6, ♀ = 5). Datapoints for individual normalized measurements are shown in each graph (*p < 0.05; **p < 0.01).