Diet-related chronic diseases have reached a critical juncture in the U.S. Nearly half the population has prediabetes or diabetes. Over 40% are overweight or obese. Though our waists are getting bigger, research is showing that the gut microbiome and the energy-producing mitochondria remain hungry for nutrients missing in our diet. This article explores the link between mitochondria and gut health, and what we can do to optimize the development of our gut microbiome.