This engaging program delves into the microscopic milieu that overlays life as human beings know it, illustrating the complex relationship between the microscopic and macroscopic worlds as the human host, with its billions of microbial allies and antagonists, journeys from the birth canal to the decomposition that follows death. Spectacular 3-D computer animation, case study footage, and expert commentary offer insights into the infiltration mechanisms of a range of pathogenic organisms; defense strategies of the digestive tract, lungs, ears, nose, and skin; positive results of probiotic therapy; and postmortem forensic research. Some content may be objectionable. (51 minutes)