EMBED: A Low Dimensional Reconstruction of Gut Microbiome Dynamics Based on Ecological Normal Modes

Abstract

The gut microbiome is well-established to be a significant driver of host health and disease. Longitudinal studies involving high-throughput sequencing technologies have begun to unravel the complex dynamics of these ecosystems, and quantitative frameworks are now being developed to better understand their organizing principles. Dimensionality reduction can offer unique insights into gut bacterial dynamics by leveraging collective abundance fluctuations of multiple bacteria driven by similar underlying ecological factors. However, methods providing lower-dimensional representations of gut microbial dynamics both at the community and individual taxa level are currently missing. To that end, we develop EMBED: Essential Microbiome Dynamics. Similar to normal modes in structural biology, EMBED infers ecological normal modes (ECNs), which represent the unique set of orthogonal dynamical trajectories capturing the collective behavior of a community. We show that a small number of ECNs accurately describe gut microbiome dynamics across data sets that encompass dietary changes and antibiotic-related perturbations. Importantly, we find that ECNs often reflect specific ecological behaviors, providing natural templates along which the dynamics of individual bacteria may be partitioned. Collectively, our results highlight the utility of dimensionality reduction approaches to understanding the dynamics of the gut microbiome and provide a framework to study the dynamics of other high-dimensional systems as well.