DPP4 and type 2 diabetes mellitus: To understand the extent to which the function of bacterial DPP4-like proteins is similar to hsDPP4 and to provide particular insights into the function of this divergent protein from those previously characterized [14, 16] (sharing ~ 52% sequence identity with those of Bacteroides species), we cloned the DPP4 gene from P. merdae, the member of the gut microbiome that is more strongly associated with T2D and the Parabacteroides species that is more abundant in the human gut [27].