Prescription drugs may alter the gut microbiome for years after a person stops taking them, according to a large study led by researchers at the Institute of Genomics at the University of Tartu.
The findings suggest that a person’s medication history may help explain long-term differences in the gut microbiota. The gut microbiome is the complex community of bacteria and other microorganisms living in the gastrointestinal tract. It plays an important role in digestion, metabolism, immune function, and overall health.
Medication effects on the gut microbiome can last for years
Researchers analyzed stool samples and prescription records from more than 2,500 Estonian Biobank participants enrolled in the Estonian Microbiome Cohort. The study found that most of the medications examined were associated with measurable differences in the gut microbiome.
For a significant number of drugs, these microbiome changes remained detectable even years after treatment had ended.
The long-term effects were not limited to antibiotics, which are widely known to disrupt gut bacteria. Antidepressants, beta-blockers, proton pump inhibitors, and benzodiazepines were also linked to distinct microbial “fingerprints.”
Beta-blockers are commonly prescribed for high blood pressure and certain heart conditions. Proton pump inhibitors lower stomach acid and are often used to treat acid reflux and related conditions. Benzodiazepines are medications frequently prescribed for anxiety and other disorders.
“While most microbiome studies only consider current medications, our results show that past drug use can be a surprisingly powerful and important factor in explaining differences in an individual’s microbiome,” said lead author Dr. Oliver Asmets.
The results indicate that researchers studying connections between the gut microbiome and disease may need to examine more than the medications a person currently takes. Drugs used months or even years earlier may continue to influence the microorganisms detected in stool samples.
Anti-anxiety medications show surprisingly strong microbiome effects
One of the most notable findings involved benzodiazepines, a class of medications commonly prescribed to treat anxiety. Their association with gut microbiota was comparable to that observed with broad-spectrum antibiotics.
Broad-spectrum antibiotics target multiple types of bacteria and can therefore cause substantial changes in the gut microbial community.
The study also found that medications within the same drug class do not always affect the gut microbiome in the same way. Drugs prescribed for similar conditions, including diazepam and alprazolam, may differ in their potential to reduce or alter gut bacteria.
This distinction is important because microbiome studies often group medications according to their drug class. The findings suggest that researchers may need to evaluate the effects of individual drugs separately.
Follow-up stool samples show predictable microbiome changes
The research team also analyzed follow-up stool samples from a smaller group of participants. These samples allowed the researchers to observe how the gut microbiome changed when people began or stopped taking specific medications.
Starting or stopping treatment was accompanied by predictable changes in gut bacteria, providing evidence that the observed microbiome differences may be caused, at least in part, by the medications themselves.
Although the follow-up analysis involved a relatively small number of participants, researchers observed lasting effects linked to proton pump inhibitors, selective serotonin reuptake inhibitors, and antibiotics such as penicillin combinations and macrolides.
Selective serotonin reuptake inhibitors are a widely used class of antidepressants. Macrolide antibiotics are used to treat a range of bacterial infections.
Past medication use may be crucial in gut microbiome research
The findings add to growing evidence that the gut microbiome reflects more than a person’s current diet, lifestyle, health status, and medication use. Previous treatments may leave biological traces that remain detectable long after a prescription has ended.
“This is a comprehensive, systematic evaluation of long-term drug effects on the microbiome using real medical health records,” said corresponding author Professor Erin Oog. “We hope this will encourage researchers and clinicians to take drug history into account when interpreting microbiome data.”
Including a person’s full medication history could help scientists more accurately distinguish microbiome changes associated with disease from those caused by drugs taken in the past.
Source: www.sciencedaily.com