Fig. 4

Heatmap of positive ion mode. Each row in the y-axis represents a significantly differential metabolite and each column in the x-axis represents a set of samples. Red represents significant upregulation of the metabolite, and blue represents significant downregulation of the metabolite. The degree of upregulation and downregulation is represented by the color depth. The metabolites with similar expression patterns are clustered in the same cluster on the left. C: Control group. OI: OI group