Gut microbiota-derived autoinducer-2 regulates lung inflammation through the gut-lung axis

Area of Science:

• Microbiology
• Immunology
• Gastroenterology

Background:

• Autoinducer-2 (AI-2) is a bacterial quorum sensing molecule.
• The gut-lung axis describes bidirectional communication between the gut and lungs.
• The role of AI-2 in lung immunity via the gut-lung axis is not well understood.

Purpose of the Study:

• To investigate the involvement of AI-2 in lung immunity through the gut-lung axis.
• To determine if AI-2 influences lung inflammation.

Main Methods:

• Analyzed AI-2 levels and gut microbiome composition in stool samples from pneumonic patients and an acute lung injury mouse model.
• Investigated the effect of AI-2 on lung inflammation in the mouse model.

Main Results:

• Reduced gut microbiota diversity was observed in pneumonic patients receiving antibiotics.
• AI-2 levels in stool correlated positively with serum inflammatory molecules in pneumonic patients.
• AI-2 administration exacerbated lung inflammation in mice, increasing inflammatory cytokine and chemokine secretion.
• An AI-2 inhibitor, D-ribose, alleviated AI-2-induced lung inflammation.

Conclusions:

• Gut microbiota-derived AI-2 plays a role in modulating lung inflammation.
• AI-2 may represent a therapeutic target for lung inflammatory diseases via the gut-lung axis.