This could be our new ally that could help control plaque build-up in arteries by neutralizing uric acid.
The war against gout and heart disease could be won in our gut, as researchers discover the power of certain bacteria to control plaque build-up in arteries by neutralizing uric acid.
Certain gut-dwelling microbes in both humans and mice could play a vital role in halting the accumulation of artery-clogging plaque, a primary contributor to cardiovascular disease, by ingesting inflammatory compounds before they enter the body’s circulation.
Pioneering research led by the University of Wisconsin–Madison and international collaborators has unveiled certain gut bacteria capable of degrading uric acid within the intestines’ low-oxygen conditions and identified the unique genes enabling this process. This study has revealed a novel way gut microbiota may impact our health and hinted at possible new approaches for gout treatment or cardiovascular disease prevention.
Uric acid is the end product when purines, essential molecules like adenine and guanine (the fundamental DNA building blocks), and indulgence molecules such as caffeine and theobromine (found in tea leaves and chocolate) break down in the human body. While healthy kidneys eliminate most uric acid, about 30% ends up in the gut. Excessive uric acid results in a painful condition known as gout.
“When your blood is saturated with uric acid, it starts to form crystals that accumulate in the joints and cause gout,” explains Federico Rey, a UW–Madison professor of bacteriology and co-author of this recently published study in the journal Cell Host & Microbe.
“But before you get enough uric acid to form crystals, even if you have a little bit more uric acid than is normal, it’s promoting inflammation in your body that is correlated with atherosclerosis—plaque building up in your arteries.”
Rey’s team collaborated with Swedish researchers to analyze data including arterial plaque, uric acid levels, and gut microbial communities from almost 1,000 individuals. They found a correlation between the amount of uric acid in their bodies and the degree of fats, cholesterol, and other substances calcifying their arteries.
They found a connection between uric acid levels and the variations of gut bacteria in these individuals. This led them to investigate whether they could pinpoint the bacteria types linked with lower uric acid levels and their association with reduced atherosclerosis, according to the author.
In their study, the UW–Madison researchers—former postdoc Kazuyuki Kasahara, scientist Robert Kerby, and graduate student Qijun Zhang—performed fecal transplants to transfer gut microbes from adult mice to germ-free newborn mice. The transplanted mice mirrored the artery health of their donors. Mice receiving microbes from donors with high uric acid levels and plaque-loaded arteries exhibited similar conditions, whereas mice with donors having lower uric acid levels and healthier blood vessels showed corresponding lower measures.
They identified the microbes associated with healthier outcomes by tracking the genes that were highly active when bacteria were cultivated in uric acid.
“That led us to a cluster of genes, found across many different types of bacteria, necessary to break down purines and uric acid in the intestine,” adds Rey. “When these purine-degrading microbes were using uric acid in the gut for their own needs there was less uric acid present in the blood of mice.”
Rey aims to explore whether introducing these purine-consuming bacteria into animals with cardiovascular issues can alleviate their conditions. For now, the team has identified a genetic marker for uric acid breakdown in the gut.
“They’re not exotic bacteria,” Rey comments.
The genes necessary for uric acid degradation were found in the microbes they already had in their lab, which can easily be cultivated.
While it’s too early to say their work could help individuals with cardiovascular disease or gout, “we have a new understanding of one way the gut microbiome modulates the abundance of this inflammatory compound, and that may point the way to new treatments.”
Image Credit: Getty