key window of vulnerability.Young children have critical periods for their growth, and our experiments are showing that the loss of friendly gut bacteria at this early stage of development is driving obesity,at least in mice.We are just beginning studies on social development and celiac disease.We have many ideas for how we can apply our findings from mouse studies to humans.Ultimately,we seek to reverse the damage seen in people around the world,including establishing strategies for restoring the missing microbes.A key step in all of our approaches is to reduce the overuse of antibiotics in our children,starting now. My odyssey over the nearly thirty-seven years since I saw that ill man in his hospital bed shivering with fever has convinced me that I am at the most critical stage of my own career.The years of working as a doctor specializing in infectious diseases and conducting scientific experiments have given me important perspectives about our modern plagues.I did not anticipate this direction when I was just starting out.But,like a series of transports,the work has carried me across the plains,mountains,and oceans of scientific medical research.It has led to new concepts about our changing modern life that I now want to share with you.The plagues today differ from those that affected my father's sisters,but they are deadly as well. 6 key window of vulnerability. Young children have critical periods for their growth, and our experiments are showing that the loss of friendly gut bacteria at this early stage of development is driving obesity, at least in mice. We are just beginning studies on social development and celiac disease. We have many ideas for how we can apply our findings from mouse studies to humans. Ultimately, we seek to reverse the damage seen in people around the world, including establishing strategies for restoring the missing microbes. A key step in all of our approaches is to reduce the overuse of antibiotics in our children, starting now. My odyssey over the nearly thirty-seven years since I saw that ill man in his hospital bed shivering with fever has convinced me that I am at the most critical stage of my own career. The years of working as a doctor specializing in infectious diseases and conducting scientific experiments have given me important perspectives about our modern plagues. I did not anticipate this direction when I was just starting out. But, like a series of transports, the work has carried me across the plains, mountains, and oceans of scientific medical research. It has led to new concepts about our changing modern life that I now want to share with you. The plagues today differ from those that affected my father’s sisters, but they are deadly as well. 15