Daijiworld Media Network - New Delhi

New Delhi, Aug 7: While antibiotics are widely known to disturb the gut microbiome, a new study has revealed that several non-antibiotic prescription drugs can also significantly alter gut bacteria and heighten the risk of gastrointestinal (GI) infections.

Researchers from Yale University, in findings published in Nature, identified a number of commonly prescribed non-antibiotic drugs that disrupt the balance of the gut microbiome. Some of these drugs, they found, can even prompt the body to produce anti-microbial agents that attack its own beneficial gut bacteria.

This microbial disruption is linked to reduced colonisation resistance — the gut’s natural ability to fend off pathogens — thereby making individuals more vulnerable to infections. The study suggests that a person’s microbiome may also explain why responses to medications can vary, potentially offering a new target for enhancing drug effectiveness.

Analysing over 10 years of health data from 1 million individuals in Canada, the researchers discovered that several non-antibiotic drugs increased GI infection risk to the same extent as antibiotics. “We found prescription drugs that increased people's risk of infections to the same degree that antibiotics would,” said lead researcher Andrew Goodman, Professor of Microbial Pathogenesis at Yale School of Medicine.

Out of 21 drugs selected for further investigation, researchers treated mice and analysed changes in their gut microbiota through faecal samples collected before and after dosing. About half of the drugs tested caused measurable shifts in microbiome composition.

Notably, four drugs stood out for both disrupting the microbiome and increasing infection risk in mice exposed to pathogens:

• Digoxin (used for heart failure)
• Clonazepam (used for seizures and anxiety)
• Pantoprazole (used to reduce stomach acid)
• Quetiapine (used for psychiatric conditions)

The findings raise questions about the broader impact of widely used medications on gut health and highlight the need for further research into microbiome-friendly approaches in drug therapy.