Few areas have received more visibility and attention over the past few years than the human microbiome. The collection of microbes that inhabit the human body have been associated with an astounding number of diseases and characteristics of human health. The promise of deciphering these microbe-host relationships are new diagnostics, therapies, and preventive measures. Despite these efforts, this is still an immature field, and there have been very few ground-breaking advances. Many of the association studies are of unclear statistical power and are often based on small cohorts. The fecal microbiota transplant technique to treat Clostridium difficile–associated diarrhea is the most publicized of the successes. Yet it is a treatment that was known before the current microbiome era and is less an outcome of current research than the type of medical innovation that arises out of strong need.