Researchers used a machine-learning framework called symclatron to search hundreds of thousands of microbial genomes from environmental samples and reference collections for genetic patterns linked to symbiosis. They placed the predictions in a new Symbiont Genomes catalog, or SymGs.

The analysis suggested that 15% to 23% of uncultivated microbes may engage in relationships with other organisms. The predicted symbionts occurred across half of all known bacterial and archaeal phyla, and showed patterns including the loss of some metabolic functions and the different presence of others that may support life dependent on a host.