Previous work has shown that certain bacterial species are transferred from parents to children. A new study from the Max Planck Institute in Tubingen suggests that part of your microbiome is actually inherited. That is, there are specific genes that regulate which bacteria thrive. To come to that conclusion, scientists correlated genetic variations to bacterial species in 1126 pairs of twins, both identical and fraternal. They found dozens of species that, while environmentally acquired, propagate due to genetics. These include species involved in gastrointestinal disorders, blood pressure regulation and autoimmunity.