Half of all Americans may be taking medications that could quietly raise their cancer risk — even years after stopping them. Researchers warn that common drugs for blood pressure, anxiety, depression, and acid reflux can harm gut health in lasting ways.
A study from Estonia found that beta-blockers, antidepressants, benzodiazepines like Xanax, and proton pump inhibitors all disrupted the gut microbiome — the community of “good” bacteria that protects your immune system. “Past drug use can be just as important as current use,” said Dr. Oliver Aasmets, one of the study’s authors.

When gut bacteria lose diversity, the body’s defenses weaken. This imbalance, called dysbiosis, can lead to chronic inflammation and a higher risk of diseases such as colorectal cancer. The researchers discovered that in some cases, harmful changes remained even three years after people stopped taking the drugs.
Experts say the findings are a wake-up call. “Every pill we take leaves a mark,” one doctor noted. Understanding how medication affects the gut could help millions protect their long-term health.