A gut-fat axis

Obesity Whether and how the gut microbiome impacts adipose tissue homeostasis is an open question. Virtue et al. showed that a high-fat diet in mice led to the activation of miR-181 in white adipose tissue (WAT). This in turn led to obesity, insulin resistance, and WAT inflammation. The increased expression of this microRNA was linked to a reduction in circulating microbiota-derived metabolites produced by tryptophan metabolism in the gut. In the plasma of obese humans, miR-181 expression was increased in WAT and indole was reduced, suggesting potential medical relevance for this axis. Sci. Transl. Med. 11 , eaav1892 (2019).