The Gut-Brain Connection
University of New Mexico scientists played a key role in new research demonstrating for the first time that changes in the gut microbiome may help trigger human neurovascular disease.
Members of New Mexico Hispanic families who share a genetic predisposition for dangerous brain bleeds known as cerebral cavernous malformations (CCM) were recruited for the study, published earlier this week in Nature Communications.
The research team found that high levels of inflammation-promoting bacteria in the digestive tract secrete lipopolysaccharide molecules, which in turn drive clusters of abnormally dilated vessels in the brain to leak blood into the surrounding tissue.
In severe cases, the condition causes seizures or stroke-like symptoms and often requires surgery, said Atif Zafar, MD, an assistant professor in the UNM Department of Neurology.
Many CCM cases appear to arise spontaneously, but Zafar and Leslie Morrison, MD, a retired professor of Neurology, have previously shown that people with northern New Mexican Hispanic ancestry are at a somewhat higher risk because of a long-ago mutation in a single ancestor that has been passed down through generations.
Both contributed to the new study, along with two dozen other researchers from The University of Chicago, the University of Pennsylvania, University of California, San Francisco and the Angioma Alliance.
These families’ willingness to participate in studies has allowed the researchers to build a rich database used in the new study, which was led by UChicago scientists, Zafar said. “Our main strength was the number of familial CCM cases that UNM has, while the Chicago group is the largest CCM patient site overall.”
UNM is one of the few CCM Centers of Excellence in the world, said Zafar, who serves as the center’s director. "We want to thank dozens of our New Mexican families, patients and healthy folks with the diagnosis of familial and sporadic CCM who participated in this trial and are the main force behind the advancements in the field.
Patients shared stool samples and their medical records for the study, which found close correlations between the prevalence of certain bacterial strains in the gut and the severity of their symptoms.
The researchers suggest that altering the diet or microbiome composition might be a way of treating the condition.
"The next step includes confirming the mini-variations that may be present even within the CCM population and to see if we can create an algorithm that can correlate how these specific gut microbiomes manipulate the severity of the disease in the CCM population,” Zafar said. “We still have a lot of work to do.”