In his book "The Longevity Paradox: How to Die Young at a Ripe Old Age," Dr. Gundry talks about a new way to age well that focuses on keeping the "oldest" parts of our bodies—the microorganisms—healthy. The role of the microbiome, the collection of bacteria that live in each person's digestive system, in determining overall health, has grown in significance over the years. As we age, these bacteria not only determine our susceptibility to life-threatening diseases such as cancer and Alzheimer's, but also to common ones like arthritis and skin aging. You can guarantee your own and other microbes' survival by providing for their nutritional requirements.