Bile acids and fat type in the diet impact metabolic responses and gut microbiota functions in mice.

To investigate metabolic consequences of primary bile acids and lard- or palm oil-based high-fat diets in mice, and study gut microbiota structure and functions.Mice were fed four different diets between the age of 10 and 18 weeks (n = 9-12 mice per diet): (I) control experimental diet; (II) control diet supplemented with 0.1 % (w/w) cholic acid and 0.1 % chenodeoxycholic acid; (III) palm oil- or (IV) lard-based high-fat diet with 48 kJ% from fat, both supplemented with bile acids as above. At the end of this experimental feeding period, mice were fasted for 6 hours. Half of the mice was sacrificed after measurement of fasting blood glucose levels from the tail vein; the other half was used for an oral glucose tolerance test (OGTT) and received therefore 2 g glucose per kg body weight via gavage.Metagenomic DNA was obtained from caecal content of fasted SPF mice (male C57BL/6) after mechanical lysis followed by column purification. The V3/V4 region of 16S rRNA genes was sequenced in paired-end modus using a MiSeq system (Illumina).