Jean-Benoit Legault, The Canadian Press
MONTREAL — Bacteria settled in the intestine seem to greatly reduce the effectiveness of drugs against hypertension, which could ultimately explain why some patients respond better than others to the medication, American researchers have discovered.
Researchers at the University of Toledo, Ohio, studied the effectiveness in mice with normal gut microbiota of a drug long used to combat hypertension, compared to mice with a normal gut microbiota. been wiped out by massive doses of antibiotics.
They found that animals in the second group responded significantly better to quinapril. They then determined that the Coprococcus bacterium was involved, since it is able to degrade quinapril and another product, ramipril.
About 20% of patients diagnosed with hypertension suffer from a resistant form of the disease, in which even aggressive treatment fails to lower their pressure to acceptable levels. Faced with such a situation, the only option available to doctors is to add or remove drugs, or even change the dose, in the hope of finally pinpointing a winning strategy.
“The study is very interesting, because resistance to hypotensive drugs that are currently available is a very important issue,” responded Professor Benoît Arsenault, from the Faculty of Medicine at Laval University.
If this study was conducted on mice, the researchers discovered an anecdotal human case which suggests that they are on the right track.
In 2015, the International Journal of Cardiology reported the case of a woman with long-standing resistant hypertension. But when the woman needed antibiotics for an infection, doctors managed to control her high blood pressure without medication for two weeks and then for six months with just one medication. His hypertension then began to resist treatment again.
American researchers agree that it is unrealistic to consider using antibiotics long-term to control hypertension. They believe, however, that a patient could alter their microbiota with probiotics, prebiotics or changes to their diet.
“We know that humans have the same bacteria in their intestines as (mice), but that’s basically all we know for the moment, said Professor Arsenault, who warns that we will have to arm ourselves with patience before this discovery finds concrete applications in humans.
“So before we think we’ve discovered a major cause of hypotensive resistance in humans…I think we have to take it and leave it.”
For obvious reasons, he reminds us, researchers are always much more eager to publish promising and spectacular results than studies that have failed. This creates a kind of “publication bias” which partly explains why preclinical results that sometimes make you dream are not always there when clinical studies begin.
Hypertension is the most common cardiovascular disease on the planet. It is nicknamed the “silent killer” since millions of people unknowingly suffer from it and it inflates the risk of other health problems, such as heart attacks and strokes.
The findings of this study were published by the medical journal Hypertension.