Abstract
Microbes occupy diverse habitats, forming interconnected, dynamic communities. Elucidating the principles of microbial community function is a grand challenge for microbiology, and it will entail experiments that engage microbiomes across multiple levels of complexity. For example, community-level hypotheses often require testing at the mechanistic and/or genetic levels, while mechanistic relationships require community-level evaluation to understand their importance in context. In this Perspective, we articulate the need for model microbiome systems that enable experimentation in both community and reductionist frameworks, with an emphasis on understanding the role of specialized metabolites in microbial communities. We consider essential criteria for developing such model microbiome systems and discuss potential future models that address the ecology of specialized metabolism.