A study led by researchers at the University of Tartu Institute of Genomics has found that medications can influence the human gut microbiome long after a person has stopped taking them. Analyzing stool samples and prescription records from over 2,500 participants in the Estonian Biobank, the researchers observed that most of the medications examined were associated with differences in the gut microbiome, with these effects persisting for years in many cases. The impact was not limited to antibiotics; drugs such as antidepressants, beta-blockers, proton pump inhibitors, and benzodiazepines were also linked to distinctive microbial “fingerprints.”
The study highlights that past drug use may be a significant factor in explaining individual differences in the gut microbiome, suggesting that researchers investigating microbiome-disease connections should consider medications used months or years prior to sample collection. Notably, benzodiazepines showed effects on the gut microbiome comparable to those of broad-spectrum antibiotics. Additionally, medications within the same drug class did not necessarily affect the microbiome in the same way, indicating that individual drugs may need to be evaluated separately in microbiome research. Follow-up samples from a smaller cohort provided evidence that starting or stopping certain medications led to predictable shifts in gut microbes, confirming persistent effects linked to proton pump inhibitors, selective serotonin reuptake inhibitors, and various antibiotics. [Source: https://www.sciencedaily.com/releases/2026/08/260824065605.htm]