The terms “micro” and “biome” are derived from Ancient Greek, where “micro” means small and “biome” means life (Berg et al., 2020). The microbiome refers to microorganisms, their genes, and the surrounding environmental conditions (e.g., pH, oxygen and substrate availability, and moisture level) (Marchesi & Ravel, 2015). Module 2 of NP 120 Part I introduces the microbiome in great detail.