For example, in a 12-week randomized, double-blind, placebo-controlled trial (NCT01744236), 51 adults with T2DM, already receiving metformin and/or sulfonylureas, were assigned to liraglutide (1.8 mg), sitagliptin (100 mg), or placebo to assess the impact of GLP-1 receptor agonism and DPP-4 inhibition on gut microbiota composition. Here, GLP1R is linked to type 2 diabetes mellitus.