For the second episode of “Science Happens,” we hung out with Pamela Silver, a scientist who wants to hack the microbiome.The microbiome — those trillions of bacteria that occupy our bodies — has become an obsession for many scientists in recent years. They are using powerful DNA-sequencing technologies to catalog the thousands of species that live in us and on us. Those experiments are revealing just how much we depend on the microbiome for our well-being. Our inner ecosystem turns out to help us digest food, influence our metabolism, nurture our immune system, and even fight off pathogens.Listen to the Signal podcast: We are a constellation of our microbiome and ourselvesScientists hope that as they come to better understand the microbiome, they’ll be able to nurture it to improve our health. In some cases, this may involve patients swallowing certain species of bacteria that can restore the ecological balance of the body.But Silver, a biologist at the Wyss Institute for Biologically Inspired Engineering in Boston, wants to try to improve on nature. By altering the DNA of gut-dwelling microbes, she and her colleagues are designing organisms that can monitor the body and produce drugs on demand. Someday, Silver’s research could lead to a new way to treat our diseases: with living medicine.