Human gut microbiota and its possible relationship with obesity and diabetes

Background Obesity and diabetes are public health problems that are leading causes of death in the world. Recent surveys suggest that there is a relationship between diabetes and bacterial residents of the gastrointestinal tract. Objective This case-control study was designed to evaluate the composition of the gut microbiota in patients with type 2 diabetes (T2DM) and obesity compared to the healthy people. Methods A total of 91 adult subjects (25 patients diagnosed with T2DM, 48 obese patients, and 18 healthy individuals) were included in the study. The gut microbiota composition was investigated by quantitative real-time polymerase chain reaction (qPCR) method using bacterial 16S rRNA gene. Results The frequency of all bacterial species in the obese group compared to the control group have significantly changed (p < 0.05) except Bacteroides fragilis, whereas the level of bacterial composition was not changed significantly (p > 0.05) in the diabetic patients versus the control ones, except for Bacteroides phylum and Lactobacillus spp. Moreover, the mean body mass index (BMI) in control, T2DM, and obese groups were 24.28 +/- 3.00, 26.83 +/- 3.29, and 44.65 +/- 3.73, respectively. Our analysis showed a positive correlation between diabetic patients plus obese ones and the number of bacteria (p < 0.05). Conclusions To sum up, these findings show that specific changes in microbial community composition are associated with T2DM and obesity. More extensive, our survey suggests that modulation of the microbiome warrants further investigation as a potential therapeutic strategy for metabolic diseases.