This study identifies gut bacteria that maintain stable, enduring relationships under various perturbations, such as dietary changes and disease states. These bacteria form a core microbiome structure of two competing guilds (TCGs), one beneficial, the other potentially detrimental, across populations and health statuses, offering a novel target for modulating human health.

Individuals can exhibit significant interpersonal variation in diet-microbiome interaction. This report uncovers how gut microbes can convert some dietary compounds into antibiotics and detoxify others, highlighting mechanisms that explain why the same dietary compound can have different effects on the microbiomes of different individuals.