Treatment with L-aspartate in cells and in mice largely replicated the beneficial metabolic effects of A. muciniphila in mice, including increased lipid oxidation, activation of the LKB1-AMPK axis and improved bile acid metabolism in the gut-liver axis, leading to the amelioration of lipid accumulation-induced metabolic disorders in the tissues of gut and liver (Figure 6/Graphic abstract). Here, STK11 is linked to metabolic disease.