Common medications may change your gut for years

A large-scale study conducted by researchers at the University of Tartu Institute of Genomics has revealed that certain medications can alter the composition of gut microbes long after a person has ceased taking them. The findings, which were based on the analysis of stool samples and prescription records from over 2,500 participants in the Estonian Biobank, indicate that a person's medical history could impact the gut microbiome years later.

The gut microbiome, which comprises a diverse community of bacteria and other microorganisms residing in the digestive tract, plays a crucial role in various aspects of health, including digestion, metabolism, immune function, and more. The researchers discovered that most of the medications examined had an impact on the gut microbiome, with some effects persisting even years after the medication had been discontinued.

While antibiotics are already known to disrupt gut bacterial populations, the study found that antidepressants, beta-blockers, proton pump inhibitors, and benzodiazepines also exhibited distinctive microbial signatures. These findings suggest that past drug usage could be as significant as current medication use when considering individual microbiome differences.

Notably, benzodiazepines, commonly prescribed for anxiety, showed effects comparable to broad-spectrum antibiotics, which are designed to target a wide range of bacteria. The study also highlighted the importance of considering individual drugs within a drug class, as different medications within the same class may have varying effects on the gut microbiome.

The researchers examined follow-up stool samples from a subset of participants and observed predictable changes in gut microbes when individuals began or stopped certain medications. These changes were attributed to the medications themselves, providing evidence that the drugs were responsible for at least some of the observed differences.

The study's lead author, Dr. Oliver Aasmets, emphasized that this comprehensive evaluation of long-term medication effects on the microbiome using real-world medical records encourages researchers and clinicians to consider medication history when interpreting microbiome data. This could help distinguish microbiome changes associated with disease from those caused by past medications, ultimately leading to a more accurate understanding of the factors influencing the gut microbiome.