How Does Infection Enrich the Gut Microbiome?

Protection against infection occurs through a combination of innate immunity and colonization resistance provided by the host's microbiome. Both defense mechanisms are strengthened by infection, although the means whereby the host microbiome is accordingly shaped are not understood.

Using a murine model, researchers showed that infection enriches the gut microbiome with Deltaproteobacteria, thereby enhancing colonization resistance. These proteobacteria utilize taurine as an energy source, ultimately converting taurine to sulfide. Indeed, livers of mice showed a postinfection shift in bile acid metabolism, increasing luminal taurine and promoting taurine-utilizing Deltaproteobacteria that contributed to colonization resistance. Sulfide restr…