This result holds in batch culture experiments (in the absence of cross-feeding), with intra-guild cohesion decreasing over time following an environmental perturbation.

For more detail, including analytics, eigenvectors, and more on cross-feeding, check out the manuscript!

Microbial communities are often highly complex at the species level, making their responses to environmental change difficult to predict. The conservation of metabolic traits across species, however, has given rise to the concept of “functional guilds,” groups of metabolically similar organisms.

We use simulation and theory to predict microbial guild response to environmental fluctuations and test these predictions experimentally. We find a shift in response depending on fluctuation rate: fast fluctuations excite cohesive intra-guild response, but cohesion disappears as fluctuations slow.