A new study published in Hypertension has shown that certain bacteria in the gut compromise the effects of some blood pressure-lowering medications.
About 20% of patients with high blood pressure, or hypertension, are resistant to certain medications; their blood pressure remains high despite undergoing treatments that work well in other patients. Researchers at the University of Toledo hypothesized that this condition, known as resistant hypertension, may be due to the bacteria colonizing these patients’ guts. To test their hypothesis, the researchers tested a representative antihypertension drug in hypertensive rats with normal gut microbiotas and identical rats who had been given antibiotics to change their gut microbiota compositions.
The rats who were given antibiotics responded much better to the antihypertension drug, indicating that one of the bacterial species in the hypertensive rats’ guts was inhibiting the effectiveness of the drug. By examining their microbiota compositions, the researchers identified a reduction in the genus Coprococcus that seemed to correlate with a better response to the drug. Further experimentation identified Coprococcus comes as the bacterial species that was breaking down the antihypertension drugs and compromising their effects.
While this study only involved animal models, Coprococcus comes is a human commensal and is likely to have a similar impact on humans. One case study identified by the researchers provided some evidence for this effect; in 2015, a woman with resistant hypertension was able to control her blood pressure for several months after taking antibiotics for a surgical infection. After about six months, her blood pressure became treatment resistant again. While more research is needed to verify the effects in humans, this research suggests that gut bacteria may play in important role in the effectiveness of some medications and especially the antihypertension medications examined in this study.