Robustness of microbiome function

Microbial communities perform metabolic processes that sustain life on Earth and promote human health. Microbial consortia sustain these functions in the face of constant structural and environmental perturbations. How do complex communities robustly sustain their functional properties despite perturbations? Most studies of functional robustness in the microbiome have been limited to biodiversity and functional redundancy, the idea that there are multiple members of the community that can sustain a specific function. Here, we propose that ideas from other complex biological systems may be applied to deepen our understanding of microbiome robustness. By surveying the causes of functional robustness in a variety of biological systems, including proteins and cells, and discussing how they can be applied to the microbiome, we build conceptual and experimental frameworks for understanding the functional robustness of microbial communities. We hope that these insights might help better predict and engineer microbiome function.