NR1H4 and infection: We found that TGR5 was significantly increased in C. sinensis-infected mice with colitis, suggesting that microbial sourced-LC-mediated TGR5 axis may be responsible for the C. sinensis-infection evoked protection of colitis, but other LCA-activated bile acid receptors such as FXR, vitamin D receptor (VDR), and sphingosine-1-phosphate receptor 2 (S1PR2), which may also be involved in the process, were not ruled out.