By Jasminee Sahoye
“The ‘signature’ of the gut micro biota – the relative abundance of various bacteria and other microbes in the digestive system – could be another useful tool in assessing a person’s risk for developing diabetes,” said Dr. Irina Ciubotaru, endocrinologist, University of Illinois (UIC) at Chicago.
Human beings have clusters of bacteria in different parts of the body, such as in the surface or deep layers of skin (skin micro biota), the mouth (oral micro biota), the vagina (vaginal micro biota) and so on.
Ciubotaru and her colleagues, including principal investigator Dr. Elena Barengolts, professor of medicine in the UIC College of Medicine and chief of endocrinology at Jesse Brown Veterans Affairs (VA) Medical Centre, found that a specific micro biota is associated with stable, normal blood glucose levels, while a different profile is associated with glucose levels that indicate pre-diabetes.
“Your gut bacteria could predict your risk of diabetes,” Barengolts said. “The study provides additional reasons for physicians to recommend foods, such as prebiotics, which improve the growth and activity of helpful gut bacteria.”
The gut micro biota helps digest food, fights infections and plays an important role in keeping the immune system healthy. It is greatly influenced by genetics, diet and other environmental factors.
Previous research has implicated an unhealthy or unbalanced micro biota as a contributing factor to metabolic disorders, including obesity and diabetes. The species that make up an individual’s gut micro biota, as well as their abundance, can be identified by stool sample analysis.
The researchers determined the gut microbiotas of 116 African-American male veterans, age 45 to 75, participating in the D Vitamin Intervention in VA, or DIVA study. The aim of the DIVA study, which has 173 total participants and is funded by the Department of Veterans Affairs, is to determine if vitamin D supplementation can prevent diabetes in men with risk factors for developing the disease.
Participants were divided into four groups based on changes in their blood sugar levels as determined at the start and end of the one-year study. The groups included men whose glucose levels remained normal (non-pre-diabetic); those with stable levels indicative of pre-diabetes; those whose levels indicated a worsening of glucose control; and those whose levels improved.
All the men provided stool samples for analysis of their gut micro biota.
Men whose blood sugar levels stayed normal over the year had more gut bacteria that are considered beneficial for metabolic health, whereas those who stayed pre-diabetic had fewer beneficial bacteria and more harmful bacteria. In addition, the group whose levels improved had more abundant Akkermansia – healthy bacteria – than the group that maintained normal blood sugar control.
The study suggests that differences in the gut micro biota already exist in pre-diabetes, Barengolts said.
Although the study found connections between composition of the gut micro biota and blood sugar control, Barengolts said further research is needed to confirm these findings and evaluate whether certain intestinal bacteria cause type 2 diabetes.
However, based on other research by her group and studies in animals, she speculated that the foods we eat affect our diabetes risk through our gut micro biota. If the mix of organisms in the intestinal tract is indeed responsible for the development of type 2 diabetes, she said, it may be possible to lower one’s risk by changing the gut bacteria.
“If we can identify those with micro biota signatures indicative of pre-diabetes, and intervene with dietary changes or other interventions that we know boost populations of beneficial gut bacteria, we may be able to prevent the development of diabetes,” said Ciubotaru.