Which gut bacteria are linked with diabetes?
It is unclear which gut bacteria are associated with the development of type 2 diabetes, Dr. Chen and colleagues write.
To investigate this, they identified 1,418 participants from the Rotterdam Study and 748 participants from the LifeLines-DEEP study enrolled from January 2018 to December 2020. Of these participants, 193 had type 2 diabetes.
The participants provided stool samples that were used to measure gut microbiome composition using the 16S ribosomal RNA method. They also had blood tests to measure glucose and insulin, and researchers collected other demographic and medical data.
Participants in the Rotterdam study were older than in the LifeLines Deep study (mean age, 62 vs. 45 years). Both cohorts included slightly more men than women (58%).
Dr. Chen and colleagues identified 126 (bacteria) genera in the gut microbiome in the Rotterdam study and 184 genera in the LifeLines Deep study.
After correcting for age, sex, smoking, education, physical activity, alcohol intake, daily calories, body mass index, and use of lipid-lowering medication or proton pump inhibitors, higher microbiome diversity was associated with lower insulin resistance and a lower prevalence of type 2 diabetes.
A higher abundance of each of seven types of butyrate-producing bacteria – Christensenellaceae, Christensenellaceae R7 group, Marvinbryantia, Ruminococcaceae UCG-005, Ruminococcaceae UCG-008, Ruminococcaceae UCG-010, and Ruminococcaceae NK4A214 group – was associated with lower insulin resistance, after adjusting for confounders such as diet and medications (all P < .001).
And a higher abundance of each of five other types of butyrate-producing bacteria – Clostridiaceae 1, Peptostreptococcaceae, Clostridium sensu stricto 1, Intestinibacter, and Romboutsia – was associated with less type 2 diabetes (all P < .001).
Study limitations include that gut microbiome composition was determined from stool (fecal) samples, whereas the actual composition varies in different locations along the intestine, and the study also lacked information about butyrate concentrations in stool or blood, the researchers note.
They call for “future research [to] validate the hypothesis of butyrate-producing bacteria affecting glucose metabolism and diabetes risk via production of butyrate.”
The authors and Dr. Shulzhenko have reported no relevant financial relationships. Dr. Steinle has reported receiving funding from the National Institutes of Health and conducting a study funded by Kowa through the VA.
A version of this article first appeared on Medscape.com.