Gut bacteria inactivates certain BP medicines leading to resistant hypertension

A new study from The University of Toledo College of Medicine and Life Sciences has shown gut bacteria can reduce the effectiveness of certain blood pressure drugs.

The research, published in the journal Hypertension, offers the first clues to what has been an elusive mystery-why do some people not respond well to medication? High blood pressure is often called a silent killer because it doesn't usually cause symptoms. However, there is a big population of individuals who know they have hypertension but still cannot get it under control, even though they're taking blood pressure drugs thereby causing a major concern.

Among those with high blood pressure, an estimated 20% have what's known as resistant hypertension, meaning their blood pressure remains high despite aggressive treatment. The only way to manage this by doctors in these patients is adding or switching medications and increasing the dose with the hope they can find something that works. Until now, there haven't had any clear indication what the mechanism is for resistant hypertension.

In recent years researchers have more intently examined the link between an individual's blood pressure readings and the unique collection of bacteria that lives in their gut.

However, this is the first study to examine the impact of gut bacteria on blood pressure medication itself. UToledo scientists compared the effectiveness of the antihypertensive drug quinapril with normal gut bacteria against those whose gut microbiota had been depleted by high doses of antibiotics. Researchers found a clear difference between the two, with those who were given antibiotics first responding much better to quinapril.