A fungal ally wards off liver disease

The human gut is home to trillions of microorganisms, collectively known as the gut microbiota. Most microbiota constituents are bacteria, which produce a diverse array of metabolites that signal to human cells or interact with enzymatic pathways to shape host biology. The microbiota also includes a range of commensal, mutualistic, and pathogenic fungi that, like gut bacteria, produce an abundance of metabolites. However, outside of a few well-studied toxin-producing pathogenic fungi, very little is known about how these fungal compounds interact with host cells to affect health. On page 491 of this issue, Zhou et al. (1) report a fungal species that resides in the human gut and produces a compound that protects against metabolic disease in mice. The findings point to intestinal fungi as a potentially rich source of beneficial chemical compounds that could be harnessed for human health.