CLEVELAND — Attention heavy meat eaters: This research is for you.
Cleveland Clinic research just expanded the link between what we eat and how the gut microbiome impacts our susceptibility to develop different diseases — in this case, how a specific gut microbe-generated byproduct is linked to heart failure risk.
Elevated levels of phenylacetylglutamine (PAG) — a byproduct created when microbes in the gut breakdown dietary protein — can be directly linked to both increased heart failure risk and severity, according to findings published in "Circulation: Heart Failure." Elevated PAG levels also were shown to correspond with types of heart failure.
For example, elevated blood PAG was observed in subjects with heart failure with preserved ejection fraction, a condition where the heart muscle doesn't relax enough between beats and becomes too stiff, making it less able to fill and consequently pump blood.
Researchers also found it's dose-dependent, meaning the more protein you eat, the higher the levels.
"Measuring blood PAG levels could provide striking value for predicting who's at risk for heart failure," says Dr. Stanley Hazen, department chair of cardiovascular and metabolic sciences at the Lerner Research Institute. "The data build a strong case that making this test available for clinicians would add to their arsenal of diagnostic tests for heart failure."
Hazen isn't saying everyone should become vegetarian — more research needs to be done. However, he is suggesting cutting back on protein, and even considering going vegetarian once a week.
The study did not distinguish which types of protein caused higher PAG levels, although previous studies indicate red meat and processed meat can raise the risk of type 2 diabetes, coronary heart disease, stroke, and certain cancers, especially colorectal cancer.
A team led by Hazen, who also serves as co-section head of preventive cardiology, previously discovered the link between PAG and cardiovascular diseases — including risk for heart attack, stroke, and death — in a 2020 study. The team of investigators found that PAG levels were linked to heart failure risks through patient data from thousands of patients in two independent study cohorts: one from Europe and another the U.S.
In other studies, introducing PAG into cardiac cells in the lab allowed researchers to better understand the mechanism behind PAG's association with heart failure, and a foundation for countering its effects.
Around 6.2 million American adults have heart failure, a condition where the heart can't pump enough blood and oxygen to meet the needs of the body. Existing treatments include lifestyle changes, like reducing sodium, or medications.
One of the next steps Hazen's team is focusing on is to identify the bacteria and their enzymes that help to produce PAG, along with development of therapeutic approaches to reduce PAG. Dietary interventions could also potentially help reduce risk.