Effect of fasting on serum BA composition in Pparafl/fl and PparaΔHep mice. A. Heat map of individual BA levels. B. Hydrophobicity index of serum bile acids. C. Total concentration of different BA classes. D. Relative percentage of different BA classes to total BAs. E. Relative fraction of individual BAs in serum of fed Pparafl/fl mice. F. Relative fraction of individual BAs in serum of fasted Pparafl/fl mice. G. Relative fraction of individual BAs in serum of fed PparaΔHep mice. H. Relative fraction of individual BAs in serum of fasted PparaΔHep mice. Σ-BAs, total BAs. T-BAs, taurine-conjugated BAs. U-BAs, unconjugated BAs. 1° BAs, primary BAs. 2° BAs, secondary BAs. 12α-OH, 12α-hydroxylated BAs. 6-OH, 6-hydroxylated BAs. Data are presented as mean ± SEM; n = 6/group. *P < 0.05 or **P < 0.01, by one-way ANOVA followed by Tukey’s post-hoc correction.