The Study On The Effect Of High Humidity Environment On The Development Of Asthma And The Intestinao Flora In Mice

Objective:Highhumidity environment is widely distributed in the world.Studies have shown that highhumidity environment has adverse effects on human physiological function and the occurrence and development of many diseases.Highhumidity environment has the most profound impact on respiratory diseases and allergic diseases.Studies have found that intestinal flora may affect the occurrence and development of asthma by affecting the body's immune status and the"gut-lung axis",while the stability and diversity of intestinal flora may be imbalanced due to the high humidity environment,thus affecting the development of asthma.There is no detailed study on the effect of highhumidity environment on body health,and the impact on asthma is limited to epidemiological investigation.In this study,we mainly studied the effects of highhumidity environment on asthmatic mice disease development and intestinal flora from the perspective of experimental zoology.Methods:?1?First of all,the damage of highhumidity environment on healthy rats was studied.48 SD rats were subjected to arterial blood gas analysis at 6h,2h,4h,8h,12h,24h,48h,and 96h.24 SD rats were randomly divided into two groups:control group and damp group.Rats were fed in normal and highhumidity environment for 30 days.The body weight,fur and feces of the two groups were recorded and observed.Blood routine indexes,liver and kidney function indexes were improved.The brain,heart,lung,liver,kidney,small intestine and spleen of the animals were examined.At the same time,the changes of oxygen partial pressure in atmospheric environment and climate simulation box were recorded.?2?To construct an animal model of dampasthma to study the effects of highhumidity environment on asthma and intestinal flora in mice.The expression of hypoxia inducible factor 1-alpha in lungs of 48 BALb/c mice at 0h,2h,4h,8h,12h,24h,48h and 96h were detected.32 BALb/c mice were divided into four groups:control group,asthma group,damp group and damp-asthma group.The body weight,fur and feces of each group were recorded and observed.The expression of blood routine parameters,Th1/Th2-related cytokines and OVA-specific IgE?OVAsIgE?in serum of mice in each group were detected after the establishment of the model.The lung pathological examination and the cell count and classification of alveolar lavage fluid were carried out.The intestinal flora diversity was analyzed by V4 region sequencing of 16S rDNA from the feces of mice in each group.On the 2nd,10th,18th and 26th days,the air microorganisms in the feeding environment and the feeding box were qualitatively and quantitatively detected.Results:?1?The results of physiological function damage of healthy rats in highhumidity environment:The partial pressure of oxygen in air environment,control box and high-humidity box was detected,and no significant difference was found between air environment and control box,and the partial pressure of oxygen in high-humidity box was significantly reduced?P<0.05?.The results of blood gas analysis showed that the concentration of PH,PCO₂,PO₂,SO₂C,K⁺,Ca²⁺,Na⁺,lactic acid changed significantly compared with 0 h group?P<0.05?.Compared with the control group,the weight of rats in the damp group increased significantly?P<0.05?.There were significant changes in erythrocyte,hemoglobin and platelet in routine blood test?P<0.05?.There were significant changes in some liver function indexes in blood biochemical tests?P<0.05?.Pathological examination showed pathological changes in lung,kidney and liver,especially in lung.?2?The effect of high humidity on the development of asthma and intestinal flora in mice:Compared with 0h group,the relative expression of HIF-1 alpha in lung was significantly different in 2h and 4h groups?P<0.05?.The expression of HIF-1 alpha in lung was mainly in alveolar epithelial cells and bronchial epithelial cells.AOD value in 2h group,4h group,8h group,12h group and 24h group was significantly higher than that in 0h group?P<0.05?.Compared with the control group,the body weight of asthma group and damp-asthma group decreased significantly?P<0.05?,and some indexes of blood routine results showed significant changes in varying degrees?P<0.05?.The lung tissue of asthma group and damp-asthma group showed different degrees of bronchial remodeling and increased alveolar spacing.The pathological changes of damp-asthma group were the most serious.Alveolar lavage fluid cell count and classification showed that inflammatory cell infiltration was the most serious in damp-asthma group.The expression of IL-4,IL-10,IFN-gamma and OVA sIgE in serum was significantly different in each group,and the change was most obvious in the damp-asthma group?P<0.05?.The number of microorganisms in highhumidity environment increased significantly?P<0.01?,and the species of microorganisms increased gradually,and the number of conditional pathogens increased.16S rDNA sequencing results showed that the OTU number of intestinal flora increased significantly in asthma group and damp-asthma group?P<0.05?,Chao index and Simpson index increased significantly in Alpha diversity?P<0.05?.The flora structure of damp group and damp-asthma group were clustered and dispersed,and the damp-asthma group was farthest away from the control group,and the number of endemic bacteria was the largest.The most pathogenic bacteria were found?P<0.05?.Conclusion:It is preliminarily confirmed that the highhumidity environment has pathological damage to lung ventilation function,acid-base balance,lung,kidney and liver in healthy rats,and has certain damage to blood function and liver function.Highhumidity environment can aggravate the development of asthma in mice.The possible reason is that it aggravates the development of asthma in mice by affecting the utilization of oxygen in lungs,the morphology of lungs and the stability and diversity of intestinal flora.