Intestinal bacteria can predict the risk of pulmonary hypertension

A team of researchers found that bacterial microflora in the human intestine could contribute to the development of pulmonary arterial hypertension (PAH). The study, entitled “Altered gut microbiome profile in pulmonary arterial hypertension patients,” in the latest issue of the American Heart Association journal Hypertension.

Normal flora of the small intestine, Lactobacillus bacteria, 3D illustration. Lactic acid bacteria. Image Credit: Kateryna Kon / Shutterstock

Normal flora of the small intestine, Lactobacillus bacteria, 3D illustration. Lactic acid bacteria. Image Credit: Kateryna Kon / Shutterstock

What is PAH?

According to experts, PAH occurs when the arteries that supply blood to the lungs are narrowed and the blood supply is compromised. This results in symptoms such as palpitations, shortness of breath and tiredness. The pressure inside the arteries of the lungs increases and this can cause the right side of the heart to fail. This is a progressive condition and can be debilitating and even life-threatening. This team of researchers has found a connection between PAH and the normal bacterial flora in the intestine. This bacterial variety inside the intestine is called a microbial flora. This new study reveals that specific types of intestinal flora could predict PAH by up to 83 percent.

What was found?

According to lead researcher Mohan Raizada, a professor in the department of physiology and functional genomics at the College of Medicine of the University of Florida in Gainesville, Florida, “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. “

I study

For this study, the team included 18 patients who were diagnosed with type 1 PAH. These patients had pulmonary blood pressure of 57.4 mm Hg. They also included 13 participants who were healthy volunteers. The intestinal flora in all participants was collected and genetic studies were used to compare the prevalence of different types of bacteria in the participants’ bowels.

results

The results revealed that in people with PAH there was an increased synthesis of “arginine, proline and ornithine” by the bacterial flora. Bacteria in PAH patients also showed an increase in “trimethylamine / trimethylamine oxide metabolism and purine metabolism” compared to healthy control volunteers. These healthy control subjects also had an increase in bacterial flora containing bacteria such as “Coprococcus, Butyrivibrio, Lachnospiraceae, Eubacterium, Akkermansia and Bacteroides”, which produced more butyrate and propionate. The team then used these images of the flora to predict whether a participant would have PAH and its algorithm was 83 percent accurate using the current analysis. Subsequently, the team performed a viromic analysis of intestinal microbes and found that those with PAH had an increase in the population of enterococcal phages and lower amounts of lactococcal phages.

According to the researchers, this was the first study to examine the connection between PAH and intestinal microbes and explained that alteration of intestinal microbes has previously been linked to various heart diseases and hypertension or hypertension.

Far ahead

Raizada said: “We were very surprised to see such an association within a small group of subjects. Usually hundreds of patients are needed to achieve this meaning.” He explained that despite the fact that intestinal microbes change often and with diet, their discovery shows that these bacteria associated with PAH appear to be largely constant. He said: “We believe these particular bacteria are constant.”

Raizada said it was unclear why intestinal bacteria affected the blood pressure inside the pulmonary arteries. He said: “We don’t know if and how intestinal bacteria and viruses go to the lungs. Some studies have indicated an increase in the incidence of intestinal leakage among people with pulmonary hypertension, which can allow some intestinal bacteria to enter the flow. blood and circulate to the lungs where they can cause inflammation and lead to vascular changes. “

As a next step, the team wants to test their findings in large populations. They expect that with high levels of accuracy, detection of these typically abnormal gut microbes could help healthcare professionals diagnose PAH early. At the moment, the diagnosis of PAH has required invasive cardiac catheterization which may be needed when symptoms become apparent. With a diagnosis based on intestinal microbes, the condition could be diagnosed earlier. The team also added that devising ways to correct microbial flora for a healthier microbiota could help treat PAH or at least stop and slow the progression of the condition. Raizada signed, “There is still the question of whether the specific microbiota associated with PAH is the cause or result of the disease; therefore, more research is needed.”

This study was supported by the National Institutes of Health (NIH), the National Center for Research Resources and the United States Department of Defense.

Source:

Specific intestinal bacteria can be associated with pulmonary arterial hypertension – https://newsroom.heart.org/news/specific-gut-bacteria-may-be-associated-with-pulmonary-arterial-hypertension?preview=a640

Journal reference:

Altered gut microbiome profile in patients with pulmonary arterial hypertension Seungbum Kim, Katya Rigatto, Marcelo B. Gazzana, Marli M. Knorst, Elaine M. Richards, Carl J. Pepine, Mohan K. Raizada, https: //www.ahajournals. org /doi/abs/10.1161/HYPERTENSIONAHA.119.14294

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Specific intestinal bacteria can predict the development of pulmonary arterial hypertension

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.

Source:

American Heart Association

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