The Relationship between Gut Microbiota Composition and Type 2 Diabetes Mellitus

Abstract

Introduction: Type 2 diabetes mellitus (T2DM) is a growing global health issue influenced by gut microbiota composition. Alterations in gut bacteria  impact  metabolic  regulation,  insulin  sensitivity,  and inflammation,  making  microbiota  a  potential  target  for  therapeutic intervention.
Methodology: A case-control study in Kirkuk City (November 2024 – March 2025) included 100 T2DM patients and 40 apparently healthy individuals as a control group. Stool and blood samples were analyzed for microbiological and immunological markers. Bacterial identification was performed using culture and biochemical tests, and interleukin (IL)- 38  levels  were  measured  via  enzyme  linked  immunosorbent  assay (ELISA). Statistical significance was set at p < 0.05.
Results: patients  with  T2DM  exhibited  increased  Escherichia  coli abundance, indicating gut dysbiosis linked to inflammation and impaired gut barrier function. Microbial diversity declined with disease duration, and differences in microbiota composition were observed in patients with hyperlipidemia and hypertension. Age-related variations suggested a higher metabolic risk in older diabetics.
Discussion: The study confirmed gut dysbiosis as a contributor to T2DM by  promoting  systemic  inflammation  and  metabolic  endotoxemia. Increased  E.  coli levels  align  with  previous  findings  on  intestinal permeability and insulin resistance. The impact of age and comorbidities on  microbiota  highlights  its  potential  as  both  a  biomarker  and  a therapeutic target. Microbiota-based interventions, such as probiotics and dietary modifications, may enhance insulin sensitivity and glycemic control.
Conclusion: This  study highlights  the link between gut  microbiota dysbiosis and T2DM, emphasizing its role in disease progression. Future research  should  explore  microbiota-targeted  therapies  to  improve diabetes management.