The human body is host to multiple different microbiomes, or communities of microbial species, which live in different environments, primarily in the gut, in the mouth, on the skin, and in the vagina. Normally, these communities are beneficial, either by providing direct benefits (e.g., gut bacteria producing short-chain fatty acids), or indirect benefits (e.g., repelling pathogenic microflora). However, when these communities are disrupted, such as by antibiotics, the balance of species in the community may shift and result in unpleasant consequences, such as antibiotic-associated diarrhea. Potential disruptors include stress, antibiotics, infection, and dietary changes.^[1]