Common Drugs May Leave Long-Lasting Imprints on the Human Gut Microbiome

In a study led by the University of Tartu Institute of Genomics, scientists analyzed stool and prescription data from more than 2,500 Estonian Biobank volunteers. They discovered that a wide range of medications—beyond the well-known impact of antibiotics—are associated with lasting changes in gut microbial composition, with effects still observable years after use. Notably, benzodiazepines produced alterations comparable to broad-spectrum antibiotics, while drugs within the same class, such as diazepam and alprazolam, showed differing impacts.

A smaller follow-up cohort confirmed that initiating or stopping drugs like proton-pump inhibitors, SSRIs and certain antibiotics led to predictable microbiome shifts. Lead author Dr. Oliver Aasmets emphasized that medication history may be a hidden confounder in studies linking the microbiome to disease. Co-author Professor Elin Org hopes the results will encourage clinicians and researchers to factor past prescriptions into microbiome analyses.