A Quantitative Theory of War and Peace in the Gut Microbiota

The gut microbiota is regarded as a densely packed microbial ecosystem. Growing data have evidenced the critical role this microcommunity plays in determining human health through its internal interactions, but it is unclear how such interactions organize into complex networks to function. Here, we propose a quantitative theory to dissect, visualize and interpret microbial interactions by inferring a directed, signed and weighted ecological network. This theory can reveal how and why gut microbes compete for resource (war) or cooperate symbiotically (peace) to reform and maintain the stability of microecological communities and predict microbial diversification, dynamics and evolution across host niches. The new theory is further incorporated into genome-wide association studies to map and identify host quantitative trait loci (QTLs) that modulate the alternative transition state of war and peace among bacteria. The discovery of such QTLs helps in designing personalized therapies that prevent microbial dysfunction to improve human health.