RESEARCH HIGHLIGHTS

摘要

Gut bacteria protect themselves from host inflammation by modifying their outer membranes. Immune responses designed to wipe out infection could, in theory, also perturb helpful flora that reside in the gut. To find out how these microbes resist the effects of inflammation, Andrew Goodman of Yale University in New Haven, Connecticut, and his colleagues studied 17 bacterial species that normally live in the human gut. They found that the microbes were all resistant to antimicrobial peptides released by hosts to kill pathogens. In the bacterium Bacteroides thetaiotaomicron, this resilience was linked to expression of a protein called LpxF, which neutralized the negative charge of the cell membrane, preventing the positively charged peptides from binding to the gut microbes surface. Mutants that did not express LpxF were outcompeted in mouse guts by other microbes during inflammation.