CLOCK and inflammatory bowel disease: Besides, BSH activity and unconjugated BAs also regulate the expression patterns of host circadian rhythm (e.g., Dbp) and other genes central to circadian clock (Joyce et al., 2014a; Joyce et al., 2014b; Govindarajan et al., 2016), which is clearly related to alterations in weight regulation and energy metabolism (Boege et al., 2021), and its disturbance causes the pathogenesis of obesity, inflammatory bowel diseases (IBD) and several liver diseases (Li and Chiang, 2014).