The diversity and number of species present within microbial communities create the potential for a multitude
of interspecies metabolic interactions. Here, we develop, apply, and experimentally test a framework for
inferring metabolic mechanisms associated with interspecies interactions. We perform pairwise growth and
metabolome profiling of co-cultures of strains from a model mouse microbiota. We then apply our framework to
dissect emergent metabolic behaviors that occur in co-culture. Based on one of the inferences from this
framework, we identify and interrogate an amino acid cross-feeding interaction and validate that the proposed
interaction leads to a growth benefit in vitro. Our results reveal the type and extent of emergent metabolic
behavior in microbial communities composed of gut microbes. We focus on growth-modulating interactions, but
the framework can be applied to interspecies interactions that modulate any phenotype of interest within
microbial communities.