Neutrophil recruitment during intestinal inflammation primes Salmonella elimination by commensal E. coli
A recent study published in Cell Host & Microbe by the Hardt group - in collaboration with scientists from D-HEST, the Vorholt group (D-BIOL), the von Mering group (UZH) - highlights the role of host immune cells in supporting gut protection by beneficial microbes against the enteric pathogen Salmonella Typhimurium.
Foodborne bacterial diarrhea is a common illness caused by complex interactions between harmful pathogens, beneficial gut microbes, and the body's immune system. Probiotics that help remove harmful bacteria are being explored as a way to reduce disease severity, but their effectiveness varies from person to person, leading to mixed results. This suggests that probiotic success depends on individual differences in gut microbiota and immune responses, though the exact mechanisms remain unclear.
Using E. coli probiotic strains, researchers have found that protection against Salmonella Typhimurium (S. Tm), a major cause of foodborne illness, varied depending on levels of gut inflammation. Specifically, they discovered that differences in the number of immune cells called neutrophils played a key role in determining the effectiveness of E. coli in fighting S. Tm. By combining multiple approaches, the team uncovered how neutrophils directly influence the competition between E. coli and S. Tm. They found that neutrophils make S. Tm more vulnerable to E. coli-mediated killing, revealing a handshake between the immune system and gut microbiota in combating enteric pathogens.
Link to the paper in external page 'Cell Host & Microbe'.