Fig. 3

Analysis of differentially abundant metabolites and enrichment pathways between the two groups. A Enhanced volcanic map of differentially abundant metabolites based on the one-dimensional criteria (P value and fold change value). Levels of each metabolite between the advanced age group and young age group were tested with the Mann–Whitney U test. In the volcano plot, the log 0.05 P value (y-axis) was plotted against the fold change (x-axis). The metabolites with 0.05 ≤ P ≤ 0.1, P < 0.05, and P ≥ 0.1 are shown with blue, green, and grey points, respectively. B Z score heatmap of an overview of differentially abundant metabolites in FF exosomes of the advanced age group and young age group. The heatmap displays the relative metabolite abundance, with red and green indicating increased and decreased levels in the advanced group versus the young group, respectively. C Metabolite set enrichment analysis depicted the metabolic pathways in which significant differentially expressed metabolites are involved between the advanced age group and young age group