Researchers identified a distinct collection of bacteria found in the gut that may contribute to and predict the development of pulmonary arterial hypertension (PAH), according to new research published today in the American Heart Association journal. Hypertension.
PAH is a chronic and progressive disease in which the arteries that supply blood to the lungs narrow, causing symptoms such as shortness of breath, heart palpitations, fatigue and others. In PAH, persistent high blood pressure in the pulmonary arteries makes the right side of the heart too hard to pump blood, resulting in heart failure of the right side (inability of the heart to pump blood properly). It is much less common than systemic blood pressure, which represents the strength of blood moving through blood vessels throughout the body.
Everyone has a collection of bacteria in the gut – known as a microbiota – which helps digestion. The researchers found that having a specific microbiota profile in the gut predicted the presence of PAH with an accuracy of 83%.
We have shown for the first time that specific bacteria in the intestine are present in people with PAH. While current PAH treatments focus on the lungs, looking at the lung / intestine axis may open the door to new therapies centered on the digestive system. “
Mohan Raizada, Ph.D., lead author of the study and distinguished professor in the department of physiology and functional genomics at the University of Florida College of Medicine in Gainesville, Florida.
For the study, stool samples were collected from 18 patients with PAH and 12 people with no history of cardiopulmonary disease. The microbiota DNA of the stool samples was isolated and sequenced. The tests revealed a group of unique bacteria in PAH-associated PAH patients.
This is the first link between a specific collection of bacteria and pulmonary arterial hypertension. However, it is not the first time that intestinal bacteria have been linked to medical conditions. A variety of different intestinal microbiota profiles have been linked to a variety of cardiovascular diseases including hypertension.
“We were very surprised to see such an association within a small group of study subjects,” said Raizada. “It usually takes hundreds of patients to achieve this meaning.”
The intestinal microbiota is constantly evolving, depending on what we eat, our environment and above all our genetic composition. However, Raizada said that PAH-associated bacteria are unique and do not appear to change: “We believe these particular bacteria are constant.”
If the results are validated in a larger study, the researchers said that the unique bacterial profile could help diagnose PAH early, probably by replacing the invasive cardiac catheterization that is used today to diagnose the disease. In addition, new types of treatment could be developed that focus on altering the intestinal microbiome of patients with PAH, providing new hope for stopping disease progression.
Another important question to research is how intestinal bacteria affect the lungs of PAH patients. “We don’t know if and how intestinal bacteria and viruses go to the lungs,” said Raizada. “Some studies have indicated a higher incidence of intestinal leakage among people with pulmonary hypertension, which can allow some intestinal bacteria to enter the bloodstream and circulate in the lungs where they can cause inflammation and lead to vascular changes.”
“There is still the question of whether the specific microbiota associated with PAH is the cause or outcome of the disease, therefore further research is needed,” concluded Raizada.
American Heart Association