Antibiotic use and gut microbiome composition links from individual-level prescription data of 14,979 individuals

This study shows that antibiotic use has long-lasting effects on the human gut microbiome, with measurable changes in bacterial diversity and composition persisting up to 4–8 years after treatment—even after just a single course. Using large-scale Swedish population data (~15,000 individuals) combining prescription records with metagenomic sequencing, the researchers found that the strongest microbiome disruptions occur shortly after antibiotic use but remain detectable years later, with variation depending on antibiotic type (e.g., stronger effects for clindamycin and fluoroquinolones, weaker for penicillin V). These findings suggest that antibiotics leave a prolonged biological “footprint” on the gut ecosystem, providing a potential mechanistic link to longer-term health risks associated with antibiotic exposure and reinforcing the importance of prudent antibiotic stewardship.