Studies explore microbiome’s link with diabetes, preterm births in minority populations

Studies designed to investigate the roles of gut microbiome among Hispanics with diabetes, as well as vaginal microbiome in preterm deliveries among black women, served as a key focus of an expert panel discussion at The Human Microbiome: Emerging Themes at the Horizon of the 21st Century.

“We’re interested in microbiota in all body sites, but we’re especially interested in research on human host microbiota interactions that may contribute to health and disease in disadvantaged populations and how those interactions are influenced by behavioral, social and environmental factors,” Michael H. Sayre, PhD, chief of research innovation at the National Institute on Minority Health and Health Disparities, said during a panel discussion at the NIH workshop.

The two studies the panel discussed are funded by NIH and are expected to be completed in 2021.

Type 2 diabetes disproportionately affects the Hispanic/Latino population in the United States. Incidence is 66% higher among adults in this group than among non-Hispanic white adults.

Emerging evidence implicates the gut microbiome as a key determinant of diabetes.

However, because different ancestral populations harbor different diabetes-associated sets of gut microbiomes, researchers at Albert Einstein College of Medicine will examine Hispanic/Latino populations with high rates of diabetes to determine the relationship between the gut microbiome and disorders of carbohydrate metabolism that may lead to diabetes.

“The project will collect and determine the genetic composition of fecal microbiome from over 2,000 cohort members,” Sayre said. “It’s the first major immunologic project focusing on microbiome of a Hispanic population.”

The preterm delivery rate among black women is nearly 60% higher than in the general U.S. population, and ascending infection is believed to be associated with a large number of those preterm deliveries. The vaginal microbiome presents a physiological barrier to ascending infection through the production of lactic acid by select organisms.

Researchers from University of North Carolina at Chapel Hill will seek to determine how unfavorable vaginal microbiome profiles may contribute to disparity in spontaneous preterm births. Additionally, risk factors such as maternal nutritional patterns, smoking, and psychosocial stress and depression will be evaluated, along with vaginal microbiome profiles.

“We are aggressively growing our portfolio of investigator-initiated research projects, and I encourage microbiome research as it relates to minority health and health disparities,” Sayre said. “Research is critical in these populations, and one thing I see as a gap is an underrepresentation of minority populations. It’s always been a problem with research in general, and we’d really like to see a greater representation because we know there are some differences in microbiota that could be traced to continental ancestry.”

The panel discussion — moderated by Lita Proctor, PhD, program director of genome sciences at National Human Genome Research Institute — also addressed other gaps in microbiome research, including the need for more trained researchers in the field, a better understanding of the functional properties of the microbiome through genetic research, and more inclusive studies that identify race and sex.

Proctor also posed a question to the 10-member panel, asking for the best microbiome sample for analysis.

“Even though saliva is easily obtained, depending on your age, your gender, how dehydrated you are, how well you brush your teeth, and whether you have periodontal disease, that saliva sample is going to have a lot of noise,” Proctor said.

Members of the joint-agency panel — led by Rajeev K. Agarwal, PhD, senior research program officer at NIH’s Office of Research on Women’s Health — unanimously agreed that stool is the most reliable human sample for testing.

“We have devoted $165 million and seven years toward studies on the environmental influences on the outcomes of children with disease and when looking at microbiomes,” Agarwal said. “The only sample that should be collected from prenatal, postnatal and different life stages is from a stool sample.” – by Chuck Gormley

Disclosure: HemOnc Today could not confirm the panelists’ relevant financial disclosures at the time of reporting.