Published online Feb 28, 2021. doi: 10.3748/wjg.v27.i8.708
Peer-review started: October 24, 2020
First decision: November 23, 2020
Revised: December 17, 2020
Accepted: January 13, 2021
Article in press: January 13, 2021
Published online: February 28, 2021
Processing time: 124 Days and 18.7 Hours
A recent investigation showed that the prevalence of type 2 diabetes mellitus (T2DM) is 12.8% among individuals of Han ethnicity. Gut microbiota has been reported to play a central role in T2DM. Goto-Kakizaki (GK) rats show differences in gut microbiota compared to non-diabetic rats. Previous studies have indicated that berberine could be successfully used to manage T2DM. We sought to understand its hypoglycaemic effect and role in the regulation of the gut microbiota.
To determine whether berberine can regulate glucose metabolism in GK rats via the gut microbiota.
GK rats were acclimatized for 1 wk. The GK rats were randomly divided into three groups and administered saline (Mo), metformin (Me), or berberine (Be). The observation time was 8 wk, and weight, fasting blood glucose (FBG), insulin, and glucagon-like peptide-1 (GLP-1) were measured. Pancreatic tissue was observed for pathological changes. Additionally, we sequenced the 16S rRNA V3-V4 region of the gut microbiota and analysed the structure.
Compared with the Mo group, the Me and Be groups displayed significant differences in FBG (P < 0.01) and GLP-1 (P < 0.05). A significant decrease in weight and homeostatic model assessment-insulin resistance was noted in the Be group compared with those in the Me group (P < 0.01). The pancreatic islets of the Me- and Be-treated rats showed improvement in number, shape, and necrosis compared with those of Mo-treated rats. A total of 580 operational taxonomic units were obtained in the three groups. Compared to the Mo group, the Me and Be groups showed a shift in the structure of the gut microbiota. Correlation analysis indicated that FBG was strongly positively correlated with Clostridia_UCG-014 (P < 0.01) and negatively correlated with Allobaculum (P < 0.01). Body weight showed a positive correlation with Desulfovibrionaceae (P < 0.01) and a negative correlation with Akkermansia (P < 0.01). Importantly, our results demonstrated that Me and Be could significantly decrease Bacteroidetes (P < 0.01) and the Bacteroidetes/Firmicutes ratio (P < 0.01). Furthermore, Muribaculaceae (P < 0.01; P < 0.05) was significantly decreased in the Me and Be groups, and Allobaculum (P < 0.01) was significantly increased.
Berberine has a substantial effect in improving metabolic parameters and modulating the gut microbiota composition in T2DM rats.
Core Tip: Recent studies suggested that the gut microbiota has an essential role in type 2 diabetes mellitus. Our study verifies the effects of berberine in regulating glucose metabolism and reducing pancreas injury in Goto-Kakizaki rats. Berberine also provides an alternative means of modulating the gut microbiota. The results revealed evidence of a decrease in Desulfobacterota, Desulfovibrionaceae, and Clostridia_UCG-014 and an increase in Verrucomicrobiota, Akkermansia, and Allobaculum. Correlation analysis indicated that fasting blood glucose was strongly positively correlated with Clostridia_UCG-014 and negatively correlated with Allobaculum.