Study On Prevention And Treatment Of Children With Recurrent Respiratory Tract Infection By Intestinal Mucosal Barrier Based On Feixi Tiaozhi Decoction

Objective:In this study,the rat model of flora imbalance and low immunity copied by antibiotics combined with glucocorticoids,which aimed to observe the effect of Chinese herbal medicine(Feixi Tiaozhi Decoction)on SIgA in rat lung tissue and colon tissue,both intestinal flora and metabolite short-chain fatty acids,tight junction protein in intestinal mucosa,and the lysozyme in the intestinal contents.In order to explore the biological basis of the role in Chinese medicine theory “supporting the defensive Qi and securing the exterior”,at the same time preliminary clarify the mechanism of regulating respiratory mucosal immune function and restoring the intestinal mucosal barrier on prevention and treatment of children with repeated respiratory tract infection by Feixi Tiaozhi Decoction,and further explore the biological basis of the theory of "Feixi Tiaozhi" in traditional Chinese medicine.Methods:1.The model of flora imbalance and low immunity of rat copied by antibiotics combined with glucocorticoids,which was successfully observed by detecting SIgA in the lung and colon tissues,intestinal flora,and short chain fatty acids in intestinal contents and tight junction proteins in intestinal mucosa.2.After the successful preparation of Feixi Tiaozhi Decoction,Chinese medicine intervention experiment was carried out by the method of gavage from the ninith day after the model was established(on the eighth day),while the positive control group was given OM-85 BV and the model group was given normal saline.The dosing phase lasted for seven days.3.Detection of tight junction proteins Claudin-1,Occludin and ZO-1 in intestinal mucosa by Western blot and Quantitative Real-time PCR.The abundance of the intestinal contents was detected by high-throughput sequencing of 16 S rRNA gene.The content of short chain fatty acids in intestinal contents was determined by gas chromatography.Determination of SIgA in lung tissue and colon tissue and the lysozyme in the intestinal contents by enzyme-linked immunosorbent assay.Result:1.The expression level of Claudin-1 mRNA in the intestinal mucosa showed a downward trend in the model group(P>0.05),while showed a rising trend in Chinese medicine intervention ones(P>0.05)especially in the FTD-Low one(P<0.05).The expression level of Occludin mRNA decreased extremely and significantly in the model group(P<0.001),while increased extremely and significantly in Chinese medicine intervention ones(P<0.001).The expression level of ZO-1 mRNA showed a downward trend in the model group(P>0.05),while increased significantly in the FTD-Low one and the FTD-Middle one(P<0.05),and showed a rising trend in the FTD-High one as well(P>0.05).2.16 S rRNA gene high-throughput sequencing results show that?At the level of the phylum:(1)Five bacteria relative abundance dominated by Bacteroidetes increased in the model group,in which six one dominated by Firmicutes and Proteobacteria reduced.(2)Four bacteria relative abundance dominated by Proteobacteria reduced in Chinese medicine intervention groups.?At the level of the genus,(1)Twelve bacteria relative abundance dominated by Alloprevotella,Bacteroides and Phascolarctobacterium increased in the model group,in which eight one dominated by Prevotella and Lactobacillus reduced.(2)Six bacteria relative abundance dominated by Alloprevotella and Clostridium XI increased in Chinese medicine intervention groups,in which six one dominated by Phascolarctobacterium and Oscillibacter reduced.3.The short chain fatty acids(acetate,propionate,butyrate)decreased significantly in the model group(P<0.05),while showed a rising trend in Chinese medicine intervention ones(P>0.05).4.The expression level of SIgA in the colon tissue showed a downward trend in the model group(P>0.05),while increased significantly in Chinese medicine intervention ones(P<0.05).The expression level of SIgA in the lung tissue extremely significant decreased in the model group(P<0.001),while increased significantly in Chinese medicine intervention ones(P<0.05).5.The expression level of lysozyme in the intestinal contents significant decreased in the model group(P<0.05),and increased significantly in FTD-Low group(P<0.01)while FTD-Middle one and FTD-High one show upward trend(P>0.05).Conclusion:1.Feixi Tiaozhi Decoction could significantly increase the level of mucosal immune molecules(SIgA)in the lung tissue,which in the rat model of dysbacteriosis and low immunity.2.Feixi Tiaozhi Decoction could repair the intestinal mucosal barrier by regulating the tight junction protein,lysozyme,flora,short chain fatty acids and mucosal immune molecules(SIgA)during the gut.3.The biological basis of the prevention and treatment of repeated respiratory tract infections in children could through repairing the intestinal mucosal barrier.