A compound produced by gut bacteria after people eat foods including pomegranates and walnuts improved heart function in experimental models of a common form of heart failure, but researchers caution that human clinical trials are still needed.
By yourNEWS Media Newsroom
A natural compound produced by gut bacteria after digesting plant chemicals found in pomegranates, walnuts and some berries could offer a new approach to treating one of the most difficult forms of heart failure, according to research from King’s College London.
The study, published in Science Advances, found that urolithin A improved heart function by as much as 80% in experimental models of heart failure with preserved ejection fraction, or HFpEF. The condition occurs when the heart can still pump normally but becomes too stiff to properly relax and fill with blood between beats, causing symptoms that can include fatigue, breathlessness and reduced ability to exercise.
HFpEF accounts for roughly half of heart failure cases and affects hundreds of thousands of people in the United Kingdom. Researchers said the condition carries a high mortality rate and remains difficult to treat because many available therapies do not directly address the stiffness and structural changes occurring in the heart muscle.
Researchers administered urolithin A in an animal model of HFpEF and then tested its effects on engineered human heart tissue in the laboratory. They found that the compound improved the heart’s ability to relax, reduced scarring and limited harmful enlargement of the heart. The human tissue experiments also showed improvements in both relaxation and contraction, providing additional evidence that the biological mechanism could potentially translate to people.
Urolithin A forms when certain gut bacteria metabolize polyphenols known as ellagitannins and ellagic acid, which are found in foods including pomegranates, walnuts and some berries. Previous research has examined urolithin A for potential anti-inflammatory, cardiovascular and neuroprotective effects, but the King’s College study identified a specific mechanism through which the compound may influence heart function.
Researchers found that urolithin A targets a protein known as PKGIα, which helps regulate blood vessels and the heart’s ability to relax. By modifying a particular site on that protein known as cysteine 42, the compound improved diastolic function and reduced cardiac remodeling in the experimental heart-failure model.
Dr. Joseph Burgoyne, senior author of the study and a cardiovascular scientist at King’s College London, said the findings raise the possibility that urolithin A could eventually be developed as a treatment or supported through dietary strategies.
“While there isn’t enough evidence to suggest that people should eat pomegranates to treat heart failure, these findings raise the possibility that diets that enhance urolithin A production may help alleviate this condition.”
That distinction is important because people vary considerably in their ability to produce urolithin A from food. Its formation depends on the composition of an individual’s gut microbiome, meaning two people eating the same amount of pomegranate or walnuts may not generate the same concentration of the compound.
Researchers are therefore not recommending pomegranates, walnuts or urolithin A supplements as treatments for heart failure. The results so far come from animals and engineered human heart tissue rather than patients with HFpEF, and clinical trials will be necessary to determine whether the improvements seen in the laboratory translate into meaningful benefits for people.
Professor James Leiper, director of research at the British Heart Foundation, which funded the study, said the early findings are encouraging but remain preliminary.
“While these findings are promising, the benefits have so far been seen in animals and engineered human tissue, so clinical trials involving people are needed to test if this approach is effective for patients. In the meantime, a healthy, balanced diet remains one of the best ways to look after your heart. Eating plenty of fruit and vegetables is linked to better heart health, but it’s important to remember that no single food can prevent or treat heart disease on its own.”
Researchers now hope the discovery can help lead to therapies that directly target the mechanisms responsible for heart stiffness and scarring in HFpEF. Urolithin A could potentially form the basis of a drug, while future studies may also examine whether dietary approaches that encourage its production provide cardiovascular benefits.
For now, the findings add to growing research into how compounds produced through interactions between food and the gut microbiome can influence organs far beyond the digestive system. But whether urolithin A can improve heart function in people with HFpEF remains a question that only human clinical trials can answer.
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