In the last few years, the study of the bacteria, archaea, microbial eukaryotes, and viruses that inhabit the human body (particularly the large intestine) has revealed a remarkable biological and functional diversity [1–6]. These organisms, collectively known as the microbiome, potentially outnumber human cells in 10:1 [7] and vastly expand on the functional capabilities provided by our genomes. Disruption in these microbial communities, also known as dysbiosis, has been causatively associated by transferring microbiomes and phenotypes to mice associated with human Kwashiorkor [8] (a wasting disease endemic to Africa) and obesity [9]. Numerous correlative associations in humans and mouse models have also been observed in a broad spectrum of complex diseases including autism spectrum disorder [10], inflammatory bowel disease [11], type 2 diabetes [12], colorectal cancer [13], depression [14] (see [15] for a detailed review on the brain-gut-microbe axis), and more.
