Type 2 diabetes is a persistent disorder in which the body fails to utilize insulin, a hormone released by the pancreas that regulates blood sugar levels. This results in increased thirst, frequent urination, fatigue, nerve damage, and a greater risk of heart disease and stroke.
According to a recent research led by Cedars-Sinai, certain gut bacteria may increase the risk of Type 2 diabetes, while others may provide protection against the disease.
According to the study, increased levels of the bacterium Coprococcus are associated with better insulin sensitivity, while increased levels of Flavonifractor in the gut microbiome are linked to decreased insulin sensitivity.
Investigators have sought to understand why people develop diabetes by looking at the microbiome, which is a collection of microorganisms that reside in the digestive tract. Studies have also found that people who don't process insulin properly have lower levels of a certain type of bacteria called butyrate.
Mark Goodarzi, MD, Ph.D., the director of Cedars-Sinai's Endocrine Genetics Laboratory, is conducting an ongoing investigation that is following and monitoring diabetic patients to see whether or not they develop the illness.
"The main question we're hoping to address is: Did microbiome differences cause diabetes, or did diabetes cause the microbiome differences?" said Goodarzi, who is the senior author of the study and principal investigator of the multicenter study called MILES.
Since 2018, MILES researchers have been collecting data from participating Black and non-Hispanic white adults aged 40 to 80 years old. An earlier cohort study from the MILES trial found that a birth by cesarean section is linked with a greater risk of developing prediabetes and diabetes.
Investigators analyzed data from 352 individuals with no known diabetes recruited from the Wake Forest Baptist Health System in Winston-Salem, North Carolina.
Investigators analyzed the data collected at the first visit, and specifically looked for bacteria that previously had been linked with insulin resistance. Each participant completed a diet questionnaire and completed an oral glucose tolerance test.
Investigators determined that 28 people had oral glucose tolerance ratings that met the criteria for diabetes. 135 people had prediabetes, a condition in which a person's blood sugar levels are elevated but not high enough to qualify for diabetes.
The research team examined connections between 36 butyrate-producing bacteria found in stool samples and a person's ability to maintain normal insulin levels. They evaluated other variables, such as age, gender, body mass index, and race, and discovered that Flavonifractor was associated with insulin resistance.
Investigators are continuing to investigate patients who participated in this investigation in order to understand how insulin production and the composition of the microbiome change over time. They are also considering how eating affects the bacterial balance of the microbiome.
Goodarzi emphasized that it is too early to know how humans may alter their microbiome in order to reduce their diabetes risk.
"That would be a bit experimental," said Goodarzi, who is also the Cedars-Sinai Eris M. Field Chair in Diabetes Research. "We need to do more research to identify the specific bacteria we need to be manipulating to prevent or treat diabetes, but it's coming, probably in the next five to ten years."
Jinrui Cui, Gautam Ramesh, Martin Wu, Osa Crago, Alain G. Bertoni, Kari E. Wong, Jerome I. Rotter, Mark O. Goodarzi, 12 August 2022, Diabetes. DOI: 10.2337/db22-0168
The National Institutes of Health, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Center for Advancement in Translational Sciences (NCATS) provided funding for the research.
