Why do functional metagenomics and synthetic biology (synbio) make such an interesting combination? This week, our new article in Nature Chemical Biology ‘The evolving interface between synthetic biology and functional metagenomics’, sheds light on how progress in synthetic biology can advance, and already have advanced, the field of functional metagenomics. We are facing a growing and aging world population, and mankind thus needs new drug molecules and ways to produce nutrients.