Common Medications May Change Your Gut for Years After You Stop Taking Them

New research reveals that many commonly prescribed medications can leave lasting changes in the gut microbiome, even years after a person has stopped taking them. The study analyzed stool samples from over 2,500 individuals in the Estonian Biobank, alongside their prescription records and data from the Estonian Microbiome cohort.

Researchers discovered that most of the medications studied were linked to differences in the gut microbiome, with some effects persisting long after drug discontinuation. This finding extends beyond antibiotics, also affecting antidepressants, beta-blockers, proton pump inhibitors, and benzodiazepines. Each drug category had its distinct microbial signature.

Lead author Dr. Oliver Aasmets emphasized that past drug use can be as significant as current medication in shaping individual microbiome differences. The findings could impact future microbiome research by highlighting the need to consider medication history when investigating links between the microbiome and disease. Experts warn that certain groups, such as babies and children, as well as older adults, may be more vulnerable to long-lasting microbiome changes due to ongoing development or declining diversity.

Benzodiazepines, often prescribed for anxiety, showed an association with gut microbiome changes comparable to broad-spectrum antibiotics. The study also noted that individual drugs within the same class may have varying effects on the microbiome, suggesting that each drug should be examined separately. While the follow-up group was small, researchers identified predictable shifts in gut microbes over time, supporting the idea that medications themselves may be responsible for some observed microbiome differences.

Lifestyle factors, like low dietary fiber intake, could also influence microbiome recovery after medication use. The researchers stress that a person's gut microbiome may reflect not just current factors but also medications taken in the past, urging scientists and clinicians to account for medication history when interpreting microbiome data.