| A large number of research results showed that the state of the intestinal flora can reflect the health level of the human body.A healthy intestinal flora is not only important for maintaining the function of the digestive system itself,but also important for the normal operation of the whole system.The diet is closely related to the state of the intestinal flora.The main component of soluble fiber in the diet is polysaccharides.This type of biomacromolecules is not easily absorbed into the blood by the intestine,and is an important nutrient and energy substance for the survival of probiotics in the intestinal flora,that is,the prebiotics in the concept of intestinal microecology.Ingestion of certain polysaccharides as prebiotics can change the intestinal flora,thus providing new ways for the prevention and treatment of various diseases.These functional polysaccharides are widely found in animals,plants,and microorganisms.So far,polysaccharides extracted from organisms from different sources have been widely used to develop functional foods and even medicinal products.As a prebiotic substance,the polysaccharides in natural products have the function of promoting the growth of intestinal flora.However,polysaccharides derived from different organisms have different biological functions.These natural polysaccharides have a broad spectrum of biological effects,such as anti-tumor,anti-cancer,antibacterial,anti-oxidant,and immune regulation.Polysaccharides from different sources vary greatly in relative molecular mass and polymer length,and the types and proportions of polysaccharides contained in them are different.Is there a difference in the recovery of flora by polysaccharides with different composition and structure? In other words,is it whether the intestinal bacteria have different polysaccharide utilization preferences,and the microbiome that preferentially uses the tested polysaccharide may cause inter-species inhibition or symbiotic reproduction to cause changes in microecological components.With the deepening of research,more and more polysaccharide prebiotics were discovered.However,the relationship between structure and function is still lacking.Therefore,if a polysaccharide with a specific structure can be linked to the specificintestinal bacteria that it acts on,it will help to target patients with different types of intestinal flora,and produce the best results.To verify this conjecture,we selected three different sources of polysaccharides,alginate polysaccharides(WP)in seaweed polysaccharides,tea tree mushroom polysaccharides(ACP)in fungal polysaccharides,and Poria polysaccharide in plant polysaccharides.(PCP).A classic antibiotic-induced flora imbalance model was used to explore the differences in the effects of these three polysaccharides on the intestinal flora of mice,and a structure-activity relationship of polysaccharides to affect the intestinal flora was initially established.Objective:First,test whether the three kinds of polysaccharides have a beneficial regulatory effect on the intestinal flora of mice,that is,whether they play a role of prebiotics.Second,we hope to provide scientific basis for precise intervention of polysaccharides in the change of intestinal flora.The individualized treatment and compound prebiotic intake provide preliminary experimental foundation and theoretical basis.Methods:1.The polysaccharide was extracted by water extraction,and the polysaccharide was concentrated by the principle that the polysaccharide can be dissolved in 60%-80%ethanol.2.BALb / C mice were randomly divided into five groups,the control group(NC),the natural recovery group(NR),the wakame polysaccharide group(WP),the Agrocybe aegerita polysaccharide group(ACP)and the Poria cocos polysaccharide group(PCP).Except for the control group,which did not do any treatment,the remaining four groups were prepared with an antibiotic intestinal flora imbalance model.Penicillin was administered at a dose of 300 mg / Kg daily for 5 days in the morning and evening.The natural recovery group(NR)and the control group(NC)did not do any treatment.The three polysaccharide groups were gavage the corresponding polysaccharides at a dose of100 mg / Kg per day.After 10 days of gavage,all mice death from neck.Mice feces,small intestinal colonization flora,and small intestine tissues were taken for subsequent research.3.Extract DNA from mouse feces and small intestinal colonization flora.Partially perform PCR-DGGE to detect the changes of passing flora and colonization flora in different groups,find specific bands and perform gel purification and sequencing operations,and perform 16 sr RNA sequencing for some DNA.As validation(biological barrier).Small intestine tissue was stained with H&E,WB was used to detect tight junction protein expression(mechanical barrier),IHC stain was used to detect MUC2expression(chemical barrier),and QPCR was used to detect intestinal cell wall immune factors IL-6,IL-10 expression(immunity barrier).Results:1.After antibiotic treatment,PCR-DGGE(Deanturing Gradient Gel Electrophoresis)detected that the diversity and richness of the antibiotic-treated group were significantly reduced compared with the control group,confirming that the model of intestinal floraimbalance was successful.2.All three polysaccharides up-regulated the expression of MUC2 in the small intestine and promoted the recovery of the small intestinal mucosal barrier.The expression of immune factors IL-6 and IL-10 also increased.3.The denaturing gradient gel DGGE showed that the three polysaccharides had differences in the intestinal flora recovery of mice with imbalanced flora.All three polysaccharides increased the richness of the intestinal flora of mice to varying degrees.The comparison of PCR-DGGE atlas of passing bacteria found that the richness of Blautia increased in the WP group,the increase of Parabacteroides in the ACP group,and the increase of Alistipes in the PCP group.The comparison of the PCR-DGGE patterns of the colony flora revealed that the richness of lactobacillus increased and the richness of Klebsiella decreased significantly in the three polysaccharide groups.16 s RNA high-throughput sequencing results showed that the Lac-Blautia richness of the three polysaccharide groups increased,the PCP group was the most significant;the WP group’s Por-parabactoides richness increased,and the PCP group’s Ver-Akkermansia richness increased significantly.Conclusion:1.All three polysaccharides play the role of prebiotics,which improves the richness of the intestinal flora and promotes the recovery of the intestinal barrier.2.The results prove that different polysaccharides have specificity for bacterial flora recovery,andprovide a theoretical basis forprecise treatment using composite prebiotics. |
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