In this study, the minimal consortium Oligo-Mouse Microbiota (OMM)12 was used to study the function of Coriobacteriia under defined conditions in gnotobiotic mice. OMM12 mice with or without adding the dominant gut bacterium Eggerthella lenta were fed with diets varying in fat content or supplemented with primary bile acids. Changes in the host liver proteomes were studied using untargeted proteomics.