The mRNAs of BA-biosynthetic enzymes in liver, namely Cyp7a1, 8b1, 27a1, and 7b1, were quantified by the QuantiGene Plex 2.0 assay. Total RNAs were isolated from mice treated with various BAs at various concentrations in diets (n = 5 per group). Data are normalized to Gapdh mRNA, and are expressed as mean ± SE. Asterisks represent statistically significant changes compared to Control.