A new study conducted at the Mayo Clinic investigates the interactions between host genome and the microbiome of the gut. The study used mice models that were meant to mimic a condition found in 20% of humans. These people cannot process the sugar metabolite fucose, which many bacteria rely on as a source of energy. The researchers found that in environments lacking this sugar, bacteria that normally processed it were forced to adapt and take on new functions. Researchers thought that conditions such as these could lead to different digestive disorders like Crohn's disease as the bacteria adopt new roles. The study showed though that the genetic makeup of the mammalian host can directly impact and shape the microbes found in its gut.