ALDH18A1 and obesity due to melanocortin 4 receptor deficiency: Blautia is a gut microbial genus that produces butyric acid and acetic acid,38 which decrease obesity by regulating G-protein coupled receptors (GPR) 41 and 43.39,40 Additionally, Blautia is one of the most abundant genera in the gut, regardless of race,34,41,42 but its relative abundance was inversely associated with VFA in the present study.