Information content of high-order associations of the human gut microbiota network.

Background: The human gastrointestinal tract is an environment that hosts an ecosystem of microorganisms essential to human health. Vital biological processes emerge from fundamental inter- and intra-species molecular interactions that influence the assembly and composition of the gut microbiota ecology. Results: Here we quantify the complexity of the ecological relationships of the infant gut microbiota ecosystem as a function of the information contained in the non-linear associations of a sequence of increasingly-specified maximum entropy representations of the system. Our paradigm frames the ecological state in terms of the presence or absence of an individual microbial taxonomic unit as a function of both the ecological states of its neighboring units and, departing from standard graphical model representations, the associations among the units within its neighborhood. Conclusion: We characterize the order of the system based on the relative quantity of statistical information encoded by high-order statistical associations of the infant gut microbiota.