Analysis Of Differences In Intestinal Microflora And Fecal Metabolomics In Rats Exposed To Dust

Objective This study used 16 SrDNA gene sequencing technology and metabolomics methods to explore the pathophysiological changes of pneumoconiosis from the perspective of intestinal flora and fecal metabolism,and provides new ideas for the study of pneumoconiosis.Methods SPF grade SD male rats were selected as experimental subjects,and were randomly divided into model group?1 mL underground coal mine dust suspension?,SiO₂ group?1 mL silica dust suspension?and normal group?1 mL sterile saline?.The collected and screened coal mine dust and purchased pure silica dust were ground into 50 mg/mL dust suspensions,and after autoclaving,non-tracheal exposure method was used to test the rats once.Samples of blood,lung tissue and feces were collected after 24 weeks of dust exposure,and the body weight of the rats was recorded.Lung tissue pathological sections and blood inflammatory factors?IL-6 and IL-11?were used to evaluate the pneumoconiosis model to reflect the disease state of the test subjects,and 16 SrDNA gene sequencing technology and UHPLC-QTOFMS non-targeted metabolomics were used to analyze the differences in intestinal flora and fecal metabolites between the experimental groups.Results 1 After 24 weeks of dust exposure,the weight of rats in the SiO₂ group was significantly lower than that in the normal group and model group?P<0.05?,and their plasma IL-6 and IL-11 expression were higher than in the normal group and model group?P<0.05?,and milky white bumps were seen on the lung surface,and the lung tissue structure was severely damaged,and there were obvious silicon nodules;the plasma IL-6 and IL-11 expressions in the model group were also higher than the normal group?P<0.05?,the lung surface was rough and dust accumulation was seen,the lung inflammation was intense,and there were a large number of cell nodules;while in the normal group,the lung surface was smooth and soft,and the alveolar structure was normal,and there was little inflammation.2 Intestinal flora detection: 1)Alpha diversity: Compared with the normal group,there was no difference in the intestinal microflora ACE and Chao1 index of the rats in the model dust group and the SiO₂ group?P>0.05?;The Shannon index of the intestinal flora of rats in the model group was significantly lower than that of the normal group and the SiO₂ group?P<0.05?,while the Simpson index was significantly higher than those of the two groups?P<0.05?;Compared with the normal group,the Simpson index of the intestinal flora of the SiO₂ group was lower?P<0.05?,but the Shannon index was not significantly different.2)Beta diversity: There were differences in microbial communities between the model group VS the normal group and the SiO₂ group VS the normal group.3)Community composition: At phylum,compared with the normal group,the abundance of Acidobacteria in rats in the model group was higher?P<0.05?,and the abundance of Actinomycetes and Proteobacteria in the SiO₂ group was higher?P<0.05?.At genus,compared with the normal group: the abundances of Ruminococcus₁,Romboutsia,Lachnospiraceae_uncultured and Lachnospiraceae_NK4A136_group in the model group were lower?P<0.05?;the abundance of Lactobacillus in the SiO₂ group was lower?P<0.05?,and the abundance of Dubosiella and Bifidobacterium was higher?P<0.05?.4)Differential flora: The abundance of Clostridia and Clostridiales in the intestinal flora of the model group was significantly lower than that of the normal group;the abundance of Actinobacteria,Actinobacteria,Corynebacteriales,Erysipelotrichia,Erysipelotrichales,Erysipelotrichaceae,Dubosiella_uncultured and Dubosiella in the intestinal flora of the SiO₂ group was significantly higher than that of the normal group,while the abundance of Lactobacillus_uncultured,Lactobacillus,Lactobacillus and Lactobacillus was significantly lower than that of the normal group.3 Fecal differential metabolites: Compared with the normal group,the content of L-fucose and 1,4-dihydroxybenzene in the feces of rats in the model group increased,mainly involved in the fructose and mannose metabolism;the content of DL-2-Aminoadipic acid,?-Citronellol,4-Nitroquinoline-1-oxide,Swainsonine,Sphinganine,Tetrahydrocortisone,1,2-dioleoyl-sn-glycero-3-phosphatidylcholine,all cis-?6,9,12?-Linolenic acid and Chenodeoxycholate in the feces of rats in the SiO₂ group increased,mainly involved in the sphingolipid metabolism.Conclusions 1 After dust exposure,the intestinal flora of the body becomes disordered.The abundance of Clostridia and Clostridiales of rats in the model group was reduced;the abundance of Actinobacteria,Actinobacteria,Corynebacteriales,Erysipelotrichia,Erysipelotrichales,Erysipelotrichaceae,Dubosiella,and Dubosiella_uncultured of rats in the SiO₂ group was increased,while the abundance of Lactobacillales,Lactobacillaceae and Lactobacillus_uncultured abundance was reduced.2 After the dust exposure,the body's fecal metabolism was disordered: A total of 2 potential metabolic markers were identified in the model group and the normal group,namely L-fucose and 1,4-dihydroxybenzene,and the content was higher than that of the normal group,where L-fucose was involved in the Fructose and Mannose metabolism;A total of 9 potential metabolic markers were identified in the SiO₂ group and the normal group,namely DL-2-Aminoadipic acid,?-citronellol,4-Nitroquinoline-1-oxide,1,2-dioleoyl-sn-glycerol-3-phosphatidylcholine,Swainsonine,all cis-?6,9,12?-Linolenic acid,Sphinganine,Tetrahydrocortisone and Chenodeoxycholate,and the content was higher than that of the normal group,where Sphinganine was involved in the Sphingolipid metabolism.Figure 31;Table 13;Reference 133...