Our body's immune system has not been that well understood to date. While immunity has been the focus of medical study from a disease perspective, many of its functional characteristics have eluded scientists. Here, in a groundbreaking compendium of immunity research, the author reveals our immune systems in a way that has vast implications for disease and wellness. The vibrant, living nature of our immune systems is documented, showing how our probiotic bacteria and yeasts interplay with our body's systems to create an ability to prevent disease and infection.