A University of Toledo researcher recently received a $2.64 million grant from the National Heart, Lung and Blood Institute to continue her groundbreaking study into how the unique colonies of tiny microorganisms living in our gut can regulate blood pressure — or lead to hypertension.
High blood pressure is one of the most common ailments among American adults. According to figures from the U.S. Centers of Disease Control and Prevention, one in three adults has hypertension. And only about half of those have their condition under control.But even those who are actively controlling their hypertension are frequently just masking the problem.
“Blood pressure medicines are not curing the cause. They are attacking it after its onset,” said Dr. Bina Joe, Distinguished University Professor and chair of UT’s Department of Physiology and Pharmacology, and director of the Center for Hypertension and Precision Medicine. “If we know that there are some bacteria that shouldn’t be there and we can correct it early on, will that lead to better health as a preventative measure?”
The hope is that the grant-funded research could ultimately lead to breakthroughs that would give clinicians a way to treat or even prevent high blood pressure by manipulating those microorganisms, also known as microbiota.
Researchers have long known that our genes can predispose us to high blood pressure. But only more recently — thanks in large part to the research by Joe’s team at The University of Toledo — has the medical community begun to realize how the microorganisms living in our bodies play a role in that equation.
“A human is an ecosystem,” Joe said. “We have one host and so many microbiota. Together they influence several traits for normal health.”
The four-year grant will allow Joe’s lab and co-investigators from her department, Drs. Matam Vijay-Kumar and Ritu Chakravarti, to dig deeper into that connection in three ways:
• First, researchers will look into how an individual’s genome determines which microorganisms flourish in their guts.
• Second, researchers will look at the effects of high salt consumption on the animals’ microbiota. Salt can kill bacteria, and it’s possible, Joe said, that high salt intake can disturb the microbiota that are beneficial to maintenance of normal blood pressure.
• Third, researchers will look at epigenetics — essentially how gene function can be altered by environmental factors and diet.
Though the work is still early, Joe and her graduate student, Saroj Chakraborty, have already been granted a patent. Researchers isolated a certain chemical called beta hydroxybutyrate that increases with exercise, but decreases with salt consumption. Joe said it’s possible that exercise benefits hypertension in part because of the higher concentration of that compound.
The lab fed hypertensive rats a precursor of that molecule to see if their blood pressure decreased.
“Sure enough, it did,” Joe said. “Our idea is if there are people who cannot exercise but they’re salt-sensitive hypertensives, here could be a magic pill. You could take a bit of this chemical so you don’t have to keep running but you can control your blood pressure. That’s unpublished data coming from this work, currently in peer review.”
Some of Joe’s earlier work on microbiota and hypertension also is getting attention for its intersection with the growing worry that overuse of antibiotics is leading to an increase in drug-resistant superbugs.
Research led by her lab found that common antibiotics could lead to a spike in blood pressure for certain individuals, while other antibiotics may actually reduce blood pressure in hypertensive patients.
The reason for that discrepancy appears to be tied to how the antibiotics interact with an individual’s microbiota.
The findings, which were recently published in the journal Physiological Genomics, could lead to additional studies that hone a more individualized approach for physicians to consider when using antibiotics to treat infection.
“I think this study is hugely important for the future of prescribing antibiotics. They’re prescribed so often to hypertensive individuals, and this study shows that can have a really negative affect on their blood pressures,” said Sarah Galla, an MD/PhD candidate, who worked with Joe on the study.
“This highlights the importance of more studies that need to be done to further the field of personalized medicine, rather than just prescribing the same antibiotic to every patient.”