Researchers analyzing data from over 200,000 adults in the UK and US have identified hundreds of gut bacteria changes associated with type 2 diabetes. The discovery was shared at the European Association for the Study of Diabetes (EASD) annual meeting held in Milan, Italy, from September 28 to October 2, pointing to how microbiome evaluations could eventually help spot vulnerable people before blood glucose elevates.
Microbiome Signatures Detected Before Blood Sugar Spikes
Changes in the composition of bacteria in the gut (the community of microorganisms that lives in the gastrointestinal tract) could provide early warning of type 2 diabetes (T2D), new research has found. By reviewing information concerning hundreds of thousands of people, researchers spotted hundreds of shifts in gut microbiome makeup that appear before any alterations show up in blood glucose measurements. This opens up the prospect of leveraging gut microbiome profiles to assist in spotting individuals who face a type 2 diabetes risk and might gain the greatest advantage from behavioral modifications. Such a method could aid preventative strategies aimed at meeting public health objectives to lower T2D diagnosis rates, according to the research team members hailing from Italy and the United Kingdom. Presently, the detection of diabetes and prediabetes—a state where blood glucose is elevated past normal limits but falls short of diabetes thresholds—relies on procedures like the oral glucose tolerance test, fasting plasma glucose, and HbA1c to spot high blood sugar concentrations. Nonetheless, these diagnostic procedures are not deployed to highlight individuals with typical blood sugar readings who remain vulnerable to developing T2D down the road. Instead, risk is currently assessed by looking at factors like age, sex BMI and family history. These latest findings represent a major step forward in understanding how our gut microbiome is linked directly with metabolic disease. Professor Tim Spector, a study co-author and Scientific Co-Founder of ZOE, pointed out that recognizing these distinct microbial shifts prior to blood sugar deterioration could enable earlier intervention involving dietary and lifestyle choices, alongside treatment alternatives, to ward off T2D.
While past investigations have uncovered strong connections between T2D and the gut microbiome, they struggled to reach a consistent consensus regarding the primary bacteria across large populations. To bring greater clarity to the subject, Dr. Gabriel Baldanzi from the Laboratory of Computational Metagenomics, Professor Nicola Segata—head of the lab within the CIBIO Department at the University of Trento located in Trento, Italy—and their UK-based colleagues analyzed metagenomic data (the DNA sequences of the bacteria living in the gut) along with health records from over 200,000 adults residing in the United Kingdom and the United States. The study involved 229,025 individuals (73.8% female, average age of 50 years). Some 3,627 had T2D and 14,022 had prediabetes. The remaining 211,376 were normoglycaemic, meaning they had a normal level of glucose in the blood.
Specific Bacterial Species Tied to Metabolic Health
Accounting for variables such as age, body mass index, and sex, the team cataloged 789 bacterial species linked to T2D. Some 168 were present at higher levels in those with the condition and 621 at lower levels. Examples include Enterocloster bolteae, which was more abundant in individuals with T2D. This species can form spores and has been previously associated with poorer cardiovascular and metabolic health. Another species, Romboutsia timonensis, was less abundant in T2D. This bacterium was only described in the last decade. Certain additional species lacked characterization, indicating they have never been isolated or grown in laboratory environments. The changes were particularly pronounced in the individuals who were taking medication for T2D. However, they also occurred in those with T2D not taking medication. The team also found that 587 of the 789 species were associated with unmedicated prediabetes.
Potential for Early Detection and Lifestyle Intervention
Following that, the investigators explored whether this distinct microbial signature appeared in participants who lacked prediabetes or T2D diagnoses yet remained susceptible to them. To test this, the team cross-referenced metagenomic profiles from 135,093 normoglycaemic participants against blood glucose measurements gathered during the two-hour window following a meal. Blood sugar temporarily rises after eating. Sustained elevation typically signals that muscle tissue fails to process insulin effectively, a condition known as insulin resistance that marks an early stage toward developing T2D. Ultimately, researchers discovered that participants whose post-meal blood sugar stayed elevated longer than normal exhibited a higher tendency to carry the gut bacteria configuration characteristic of T2D.