Drawing drugs out from the dark matter

Many of our most potent medicines — antibiotics, say — already are derived from microbes. But there’s still an entire universe of bugs from which we may harvest new drugs, and many may reside in our own mouths and guts. Two research groups, highlighted in Science, are analyzing the DNA of bacteria that make up the human microbiome’s so-called “dark matter.” 

The research has turned up some interesting findings: For instance, one study used metagenomic data to gather clues about what kinds of molecules were produced by the microbiome. In the process, scientists discovered a series of new genes that coded for a class of molecules called aromatic polyketides — among which include the antibiotic tetracycline and the cancer drug doxorubicin. 

When those genes were then inserted into lab bacteria, they produced a new set of chemicals. None had anticancer properties, but two worked as powerful antibiotics.

“It is amazing to think that the human microbiome has genes to make countless complex chemicals, but we don't know what those chemicals are,” Eric Schmidt, a University of Utah chemist, told Science.