In line with these studies, Kuang et al. recently reported that cyclically induced expression of histone deacetylase 3 (HDAC3) in gut epithelial cells mediates the diurnal programming of the host’s metabolism by the intestinal microbiota, the lack of which leads to diet-induced obesity [156]. Here, HDAC3 is linked to obesity due to melanocortin 4 receptor deficiency.