Prospects for systems biology and modeling of the gut microbiome.

Abundant microorganisms that inhabit the human intestine are implicated in health and disease. The gut microbiome has been studied with metagenomic tools, and over 3 million genes have been discovered, constituting a 'parts list' of this ecosystem; further understanding requires studies of the interacting parts. Mouse models have provided a glimpse into the microbiota and host interactions at metabolic and immunologic levels; however, to provide more insight, there is a need to generate mathematical models that can reveal genotype-phenotype relationships and provide scaffolds for integrated analyses. To this end, we propose the use of genome-scale metabolic models that have successfully been used in studying interactions between human hosts and microbes, as well as microbes in isolation and in communities.