Antibiotic-induced gut microbiota disruption during human endotoxemia: a randomised controlled study

Area of Science:

• Immunology
• Microbiology
• Pharmacology

Background:

• The gut microbiota plays a crucial role in immune system development and modulating systemic immunity during sepsis.
• Disruption of the gut microbiota by antibiotics may lead to immunosuppression, potentially worsening conditions like sepsis.

Purpose of the Study:

• To investigate whether disrupting the gut microbiota with broad-spectrum antibiotics affects systemic innate immune responses during experimentally induced endotoxemia in healthy human subjects.

Main Methods:

• A proof-of-principle intervention trial involving 16 healthy young men.
• Participants received either broad-spectrum antibiotics (ciprofloxacin, vancomycin, metronidazole) for 7 days or no treatment.
• Endotoxemia was induced intravenously with lipopolysaccharide, and blood and fecal samples were collected for analysis.

Main Results:

• Antibiotic treatment significantly reduced gut microbiota diversity in all subjects.
• No significant differences were observed in clinical parameters, neutrophil influx, cytokine production, coagulation activation, or endothelial activation between antibiotic-treated and control groups during endotoxemia.
• Antibiotic pretreatment did not alter blood leukocyte responsiveness to Toll-like receptor ligands or common sepsis pathogens.

Conclusions:

• Gut microbiota disruption by broad-spectrum antibiotics does not appear to impact systemic innate immune responses in healthy humans during endotoxemia.
• These findings contradict the hypothesis and suggest caution in translating animal model findings directly to human physiology.
• Further research is warranted in critically ill patient populations to confirm these results.