Changes in the gut microbiome can indicate a person's risk of developing type 2 diabetes before blood sugar levels show noticeable increases, according to research presented at the annual conference of the European Association for the Study of Diabetes.
Researchers analyzed the gut bacteria composition and health records of 229,025 people across the United Kingdom and the United States to examine how microbial communities relate to metabolic health.
The study cohort included 3,627 participants diagnosed with type 2 diabetes, 14,022 individuals with prediabetes, and more than 211,000 individuals whose blood glucose levels remained within normal ranges.
Scientists identified 789 species of gut bacteria that were directly associated with diabetes. Among these microorganisms, 168 species were present in higher quantities in patients with the condition, while 621 species were found in lower amounts.
The gut microbiome consists of trillions of microorganisms residing in the human digestive tract that play an essential role in digestion, metabolism, and immune health. Type 2 diabetes is a chronic metabolic condition where the body becomes resistant to insulin or fails to produce enough of the hormone, leading to elevated blood sugar levels over time.
Early signs of insulin resistance
In a separate analysis of more than 135,000 participants with normal blood sugar levels, researchers examined how glucose levels behave after meals. They found that individuals whose blood sugar remained elevated for longer periods after eating already possessed gut microbiomes that closely resembled the bacterial profile characteristic of diabetes.
The researchers observed that as early signs of insulin resistance became more pronounced, changes in the gut microflora were noticeably more distinct. This suggests that the restructuring of the gut microbiome occurs before metabolic dysfunction becomes apparent during routine blood sugar assessments.
Insulin resistance develops when cells in muscle, fat, and liver tissue do not respond effectively to insulin and cannot easily absorb glucose from the blood. Prediabetes occurs when blood sugar levels are higher than normal but do not meet the diagnostic threshold for full diabetes, affecting millions of adults worldwide.
Standard blood testing for diabetes typically measures fasting plasma glucose or glycated hemoglobin levels. However, these conventional measurements track glucose concentration in the bloodstream rather than the underlying cellular and bacterial changes that precede glucose elevation.
Future screening and health risks
Scientists reported that evaluating the gut microbiome could in future complement existing screening tools to assess diabetes risk. Early detection using microflora analysis could help medical professionals identify individuals who would benefit from early interventions, including tailored diet and lifestyle modifications.
Dietary changes, weight management, and regular physical activity are widely recognized as primary non-pharmacological approaches to prevent or delay the onset of type 2 diabetes in individuals at risk.
The study builds on earlier medical research which established that individuals diagnosed with type 2 diabetes face a higher statistical likelihood of developing various types of cancer.
The European Association for the Study of Diabetes is an international medical organization founded to encourage research into diabetes, rapidly diffuse acquired knowledge, and facilitate its application to clinical practice across Europe and internationally.
