Venturelli, O. S. et al. Mol. Syst. Biol. 14, e8157 (2018).

The human gut harbors hundreds of species of microorganisms, thought to play a role in metabolism and disease. Interactions between species are likely to influence the functional properties of the microbiome, but are difficult to study. Venturelli et al. examined a synthetic 12-species, 4-phylum community of anaerobic microorganisms modeling those in the human gut. The researchers grew organisms in monospecies, dual-species, or more complex cultures and monitored them over time, using 16S RNA profiling to determine composition. They observed several outcomes: single-species dominance, stable coexistence, and historical dependence where the order of inoculation influenced outcome. They modeled the dynamics of these cultures, identifying positive and negative interactions. They further predicted the behavior of 11-member cultures with a model trained on dual-species data, indicating that pairwise interactions are a major driver of multi-species dynamics.