Figure 2.

Cecal concentration of SCFAs and fecal level of bile acids in mono-associated mice. (a) Acetate, propionate and butyrate concentration were determined in cecal content by gas chromatography coupled with mass spectrometry. Results are expressed as mean±s.e.m. (n=5 per group). Statistical comparison with the germ-free group was performed using Mann–Whitney U-test (*P<0.05/**P<0.01/***P<0.001). (b) Bile acid composition was measured in feces at 6 weeks post-gavage by high-performance liquid chromatography coupled to tandem mass spectrometry, and was represented here with the concentration of bile acid families or individual bile acid proportion. Results are expressed as mean of five mice per group.