Delong Meng, Zhen Zhang, Tsegay Teame, Benjamin Earl Niemann, Rui Xia, Shichang Xu, Yajie Zhao, Yalin Yang, Chao Ran, Le Luo Guan, Zhigang Zhou
Evidence for liver metabolism of gut-derived microbial compounds into beneficial secondary metabolites has been lacking. Here, we demonstrate that Cetobacterium somerae (C. somerae), enriched by mannose supplementation under high-fat diet conditions, convert arginine into putrescine. The liver subsequently converts this microbial-derived putrescine to spermidine, which functions as an effector molecule to reduce hepatic lipid accumulation. These findings uncover a novel host-microbiota collaborative mechanism in which the arginine-putrescine-spermidine metabolic pathway is completed through inter-kingdom cooperation to ameliorate hepatic steatosis.