PDE4A and type 2 diabetes mellitus: Metformin treatment reversed type 2 diabetes-associated gut microbiota changes, with the composition of the gut microbiota, including Akkermansia levels, resembling nondiabetic controls.47 In addition, Tuhuaiyin, a kind of Chinese herb, was reported to alleviate IMQ-induced psoriasis-like phenotype companied with the remodels of the gut microbiota.48 In our study, we found that treatment with PDE-4 inhibitors contributed to the recovery of intestinal microbiota in psoriasis-like mice, including Parabacteroides distasonis and Prevotella levels.