Figure 3. Increased plasma TMAO levels are associated with cognitive declines in C57BL/6J mice. Principal component analysis (PCA) data derived from behavioral experiments of mice with or without choline supplementation (A). Each axis was derived by PCA. Each point represents one of the mice with or without choline. Principal component 1 (variance explained: 89.78%), principal component 2 (variance explained: 6.58%) considered significant variance with a load below or equal to 0.50 (absolute value). The mean PCA scores of mice with or without choline (B). Receiver operating characteristic (ROC) curve plots for distinguishing choline-treated mice from control mice based on a TMA- or TMAO-based random forest model (C). Spearman correlation between the TMA, TMAO concentrations and cognitive impairments in WT and APP/PS1 mice (D). **P<0.01, versus the C57BL/6J mice, by unpaired Student's t-tests. All values are mean ± S.D. n=30.