Firmicutes/Bacteroidetes Ratio in the Gut Microbiota and IL-1β, IL-6, IL-8, TLR2, TLR4, TLR5 Gene Expressions in Type 2 Diabetes.

Background: The aim of this study was to determine the Firmicutes/Bacteroidetes ratio in the gut microbiota and IL-1β, IL-6, IL-8, TLR2, TLR4 and TLR5 gene expression levels in the blood of adult type 2 diabetes (T2D) patients and compare it with that of adult nondiabetic healthy controls (HC).

Methods: Between May 2016 and April 2017, 99 T2D patients and 99 HCs were enrolled in the study. Bacteroidetes and Firmicutes levels were assessed from stool sample DNA and IL-1β, IL-6, IL-8, TLR2, TLR4, and TLR5 gene expression levels assesed from blood sample RNA via qPCR from both T2D patients and healthy controls.

Results: The Firmicutes/Bacteroidetes ratio detected in the stool of type 2 diabetes patients was found to be higher with a statistically significant difference (p < 0.0001). Gene expression levels of IL-1β, IL-6, IL-8, TLR2, TLR4, and TLR5 were found to be upregulated.

Conclusions: The highest upregulation was detected in IL-6 with 11 fold in T2D patients comparing with HCs. F/B ratio and gene expression levels were elevated in T2D patients. Firmicutes were positively correlated with studied gene expressions. A better understanding of the complex interaction between gut microbiota, environment, and diabetes will allow for more effective prevention and treatment strategies for T2D.