Figure 4.

Impact of Rb supplementation on plasma metabolite levels. Panel (A) shows a volcano plot of paired comparisons between metabolite plasma levels in pre- and post-supplementation groups. On the x-axis, a count of significant sample pairs is shown. On the y-axis, the minus logarithm of paired t-test p-values is shown. Metabolites showing statistically significant changes following the Rb supplementation (p-value < 0.05 and fold change > 1.25) are depicted as blue dots on the right (increase) and left (decrease) top corners. Top-three significantly different metabolites of both increasing and decreasing values are labeled. Panel (B) shows top metabolites showing significant changes following Rb supplementation. Box and whisker plots show median, first, and third quartiles, and maximum and minimum values for the 24 sample pairs before (Pre) and after (Post) the Rb supplementation. The three metabolites, which exhibited the most significant decrease and increase following the supplementation, are shown on the top and bottom rows, respectively. Green and red lines stand for increasing or decreasing plasma metabolite levels between pre- and post-supplementation states within individual paired samples. Panel (C) shows a bi-dimensional score plot depicting the distinct plasma metabolomic profile between pre- (red dots) and post-supplementation (green dots) paired participants. The two principal components of the smPLS-DA model along with their corresponding variance in group discrimination are shown on y- and x-axis, respectively. Panel (D) shows a loading plot representing the top 10 metabolites selected on the first component of the smPLS-DA model. Most important metabolites in group discrimination are ordered according to their loading weights (horizontal bars), from bottom to top. Bar color indicates the group for which the mean value is the highest for each feature (orange and green stand for pre- and post-supplementation groups, respectively).