Do Antibiotics Worsen Lung Immunity During Flu?

TOPLINE:

Antibiotic use during influenza infection increases lung eosinophils, impairing immunity against secondary bacterial pneumonia. This study highlights the detrimental effects of antibiotics on lung health during viral infections.

METHODOLOGY:

• Researchers conducted a murine model study to evaluate the impact of antibiotic use during influenza infection on lung immunity. Mice were treated with a broad-spectrum antibiotic cocktail (vancomycin, neomycin, ampicillin, and metronidazole) starting 7 days before influenza infection.
• The study included intranasal infection with influenza virus followed by a secondary challenge with methicillin-resistant Staphylococcus aureus (MRSA).
• Lung eosinophils, macrophage function, and MRSA clearance were assessed through various immunologic and histologic analyses.
• Finally, in sub-study, a total of three cohorts of hospitalized patients were evaluated to correlate eosinophil levels with antibiotic use, systemic inflammation, and outcomes.

TAKEAWAY:

• Antibiotic use during influenza infection impairs lung immunity, leading to increased lung eosinophils and reduced macrophage function.
• The study found that antibiotic treatment during influenza infection caused fungal dysbiosis, driving lung eosinophilia and impairing MRSA clearance.
• The detrimental effects of antibiotics on lung immunity were specific to the two-hit model of influenza followed by MRSA infection in mice.
• In hospitalized patients, eosinophil levels positively correlated with antibiotic use, systemic inflammation, and worsened outcomes.

IN PRACTICE:

“Our study highlights the pernicious effects of antibiotic use during viral infections and defines a mechanism whereby antibiotics perturb the gut mycobiome and result in lung eosinophilia. In turn, lung eosinophils, via release of MBP-1, suppress alveolar macrophage clearance of bacteria,” the authors of the study wrote.

SOURCE:

This study was led by Marilia Sanches Santos Rizzo Zuttion, Cedars-Sinai Medical Center in Los Angeles. It was published online in The Journal of Clinical Investigation.

LIMITATIONS:

This study’s limitations included the use of a murine model, which may not fully replicate human immune responses. Additionally, the study focused on a specific antibiotic cocktail, and results may vary with different antibiotics. The findings were also specific to the two-hit model of influenza followed by MRSA infection, limiting generalizability to other infections.

DISCLOSURES:

This study was supported by grants from the National Institutes of Health. Marilia Sanches Santos Rizzo Zuttion received research funding from Pfizer Inc. Additional disclosures are noted in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.