Published online Oct 21, 2023. doi: 10.3748/wjg.v29.i39.5471
Peer-review started: July 14, 2023
First decision: September 6, 2023
Revised: September 11, 2023
Accepted: October 11, 2023
Article in press: October 11, 2023
Published online: October 21, 2023
Processing time: 91 Days and 13.4 Hours
The exact mechanism by which mid-small intestinal bypass (MSIB) improves glucose metabolism in diabetic rats is not fully understood.
To explore the role of the mid-small intestine in the onset and progression of diabetes.
The aim of this study was to elucidate the mechanisms by which MSIB improves glucose metabolism.
Streptozotocin was used to induce diabetes mellitus in Sprague-Dawley rats at a dose of 60 mg/kg. The rats were then randomly divided into two groups: The MSIB group and the sham group (underwent switch laparotomy). Following a 6-wk recovery period post-surgery, the rats underwent various assessments, including metabolic parameter testing, analysis of liver glycogen levels, measurement of key gluconeogenic enzyme activity, characterization of the gut microbiota composition, evaluation of hormone levels, determination of bile acid concentrations, and assessment of the expression of the intestinal receptors Takeda G protein-coupled receptor 5 and farnesoid X receptor.
The MSIB group of rats exhibited improved glucose and lipid metabolism, increased hepatic glycogen content, and decreased expression of key gluconeogenic enzymes (phosphoenolpyruvate carboxykinase 1 and glucose-6-phosphatase). Notably, this group showed a substantial rise in specific intestinal bacteria, including Lactobacillus, Clostridium symbiosum, Ruminococcus gnavus, and Bilophila. Additionally, elevated levels of secondary bile acids, such as lithocholic acid, were observed. Importantly, changes in the gut microbiota were significantly correlated with the expression of gluconeogenic enzymes and glucagon-like peptide 1 (GLP-1) at 6 wk post-surgery, suggesting their potential involvement in regulating glucose. These findings underscore the beneficial impact of mid-small intestine bypass on glucose metabolism and its modulation of the gut microbiota.
This study shows that postoperative introduction of intestinal Clostridium symbiosum in the mid-small intestine improves glucose metabolism in non-obese diabetic rats. This enhancement is linked to increased inhibition of hepatic gluconeogenesis mediated by GLP-1, leading to a positive impact on glucose regulation.
This study explores partial mechanisms of the interaction between gut microbiota and host metabolism, providing a theoretical foundation for non-surgical interventions in diabetes-related metabolic disorders.