Main gut bacterial composition differs between patients with type 1 and type 2 diabetes and non-diabetic adults.

Background: Regarding the role of gut microbial dysbiosis in hyperglycemia, we aimed to compare the main gut bacterial composition among type 1 and type 2 diabetic patients and healthy non-diabetic adults.

Methods: A total of 110 adult subjects (49 patients diagnosed with type 2 diabetes, 21 patients diagnosed with type 1 diabetes and 40 healthy persons) were included in this case-control study. The intestinal microbiota composition was investigated by quantitative real-time polymerase chain reaction (qPCR) method targeting bacterial 16S rRNA gene. Comparison between three groups was done using one-way analysis of variance.

Results: The participants' mean age in the type 1 diabetes, type 2 diabetes and control groups was 35.4, 57.2 and 38.0 years, respectively. Higher level of , and was observed in both type 1 and type 2 diabetic patients compared with the healthy group (P ˂0.001). In contrast, bacterial load of , and was higher in healthy control group ( < 0.05). was significantly lower in type 1 diabetic patients compared with the other two groups (P ˂0.001). No significant difference was found in level among three groups.

Conclusions: Gut microbial alterations have been observed among patients suffering from type 1 and type 2 diabetes mellitus and healthy control adults. Butyrate producing genera including and decreased while , and increased in diabetic patients compared to healthy subjects. Modulating approaches of gut microbiota composition could be helpful in diabetes management.