Effect of OCA administration on luminal bile acid concentrations in the murine small intestine and feces. Total (endogenous bile acids and OCA), total endogenous, total primary, and total secondary bile acids in the (A) lumen of the proximal small intestine; (B) lumen of the distal small intestine, and; (C) feces of mice following 14 days of gavage with either water (control, N=5), 0.5% methylcellulose (MC, N=10), or 0.5% methylcellulose with 10 mg/kg obeticholic acid (OCA, N=10). Mean±SE, *p<0.05, **p<0.01, ***p<0.001. Heatmaps of luminal bile acid concentrations in the proximal (D) and distal (E) small intestine.