| The incidence of gestational diabetes mellitus(GDM)is increasing in recent years,causing harm not only to the health of pregnant women but also to offspring.Studies have shown that obesity is one of the important factors causing GDM,and oxidative stress is a critical pathogenesis of GDM.Besides this,GDM is also affected by genetics,intestinal flora,diet and other factors.Xylo-oligosaccharides(XOS)act as a prebiotic to regulate the intestinal flora and improve the health of the body.The preliminary research of the research group showed that XOS can effectively alleviate GDM,and with the help of intestinal microbiota metagenomic sequencing technology,it was found that XOS can improve the antioxidant function of the intestinal flora of pregnant women,especially the significant enrichment of glutathione metabolic pathway,and the key strains Megasphaera elsdenii and Bifidobacterium pseudocatenulatum were predicted for XOS.However,the mechanism of action of the two bacteria to alleviate GDM is still unclear.Therefore,it is of great significance to isolate and culture Megasphaera elsdenii and Bifidobacterium pseudocatenulatum and explore the mechanism of metabolism XOS to improve oxidative stress during pregnancy through glutathione metabolism pathway,which is vital important for the prevention and improvement of GDM.In this study,the key strain M for alleviating GDM was isolated and cultured from the feces of pregnant women with GDM who underwent XOS intervention M.elsdenii p SML and B.pseudocatenulatum JNFE15.On the one hand,we explores the relationship between the two bacteria in the process of metabolizing XOS and antioxidant effect through in vitro fermentation experiments;On the other hand,4-week-old C57BL/6J female mice were used to construct an obese pregnant mouse model with high-risk factors for GDM by high-fat diet and cage treatment,and the improvement mechanism of XOS fermented by double bacteria on GDM was further verified by in vivo experiments.In addition,a combination of 16 S r RNA sequencing technology and metabolomics technology was used to determine the specific metabolic pathway of two-bacteria fermentation XOS to mitigate GDM.In vitro experimental part,the key species was screened from feces.M.elsdenii p SML is currently deposited in Guangdong Microbial Culture Collection Center(GDMCC)under registration number: GDMCC No:62902;key species B.pseudocatenulatum JNFE15 is preserved in this group.The results of in vitro fermentation experiments showed that M.elsdenii and B.pseudocatenulatum has a synergistic relationship when it co-metabolizes XOS,which can increase the production of GSH and T-GSH in fermentation broth.In vivo experimental part,this study found XOS and B.pseudocatenulatum can improve insulin sensitivity(P<0.05);XOS and M.elsdenii in combination can increase blood catalase levels(P<0.05);XOS and the combination of M.elsdenii and B.pseudocatenulatum not only significantly reduced the body weight of mice(p<0.05),but also significantly increased the content of reduced glutathione in the blood of mice(p <0.05),which also had a tendency to improve insulin resistance in mice.Through the analysis of intestinal flora Lef Se,it was found that the key species changes of monobacterial intervention and mixed bacterial intervention were concentrated in the firmicute phylum.Via the structural changes of the intestinal flora,it was found that the intervention could change the composition of the firmicutes in the intestinal tract of mice,increasing the abundance of verrucous microbacteria,and reducing the abundance of Proteobacteria to regulate intestinal health.In addition,the determination of M.M.by metabolomics and intestinal function prediction was established M.elsdenii and B.pseudocatenulatum synergistically metabolizes XOS and participates in the citric acid cycle and glutathione metabolic pathway to improve specific pathways of oxidative stress.The above study shows that M.elsdenii and B.pseudocatenulatum can synergistically metabolize XOS,reduce body weight,improve oxidative stress,regulate intestinal flora and improve glutathione production,achieve the effect of alleviating GDM,and provide new ideas for the prevention and treatment of GDM. |
