Blood microbiota composition in Iranian pre-diabetic and type 2 diabetic patients1

Type 2 diabetes as the most prevalent metabolic disorder, is one of the major causes of morbidity and mortality worldwide. Recent studies suggest that body microbiota may play a role in developing metabolic disorders including type 2 diabetes. The objective of the present study was to investigate the blood microbiota composition in Iranian pre-diabetic and type 2 diabetic patients compared to healthy individuals.Blood samples were taken after 12-h fasting from 90 participants, 30 healthy individuals, 30 type 2 diabetes patients and 30 pre-diabetic participants. The buffy coat layer separated by centrifugation at 800 and DNA was extracted using a column-based method. Composition and load of blood microbiota was evaluated by real-time PCR method using genus specific 16S rRNA primers.The load of Akkermansia, and Faecalibacterium was higher in normal volunteers compared to pre-diabetic and type 2 diabetes group (p< 0.05).The load of Bifidobacterium was higher in normal volunteers compared to type 2 diabetes patients (p= 0.02). In contrast, the load of Lactobacillus and Escherichia coli was higher in pre-diabetics and type 2 diabetes patients compared to normal volunteers (p< 0.05).The load of Bacteroides fragilis was not statistically different between studied groups but it was higher in males compared to female group (p= 0.04). the load of other bacteria was not significantly different between male and female participants.There is difference between microbiota composition in white blood cells of pre-diabetic and type 2 diabetes patients compared to healthy people. Determination of blood microbiota pattern may have a role in diagnosis and preventive of type 2 diabetes in a certain population. For more clarification about correlation between blood microbiota and type 2 diabetes, larger studies with more participants in different ethnical populations is suggested.