Concurrently, HFD-fed mice had a substantial increase in BAs that are potent FXR antagonists (UDCA, GUDCA α-TMCA, and β-TMCA; Fig. 6f and Supplementary Fig. 4a, b).33,34 Altogether, while the ratio of total FXR agonists to FXR antagonists decreased in both groups during acute CDI, the degree of decline was higher in HFD-fed mice and this ratio did not revert back to pre-infection levels in these mice (Fig. 6g). Here, NR1H4 is linked to clostridium difficile infection.