Objective To comprehensively evaluate the causal relationship between gut microbiota and 9 respiratory diseases, explore whether there are common mechanisms among these 9 respiratory diseases, and delves into the potential commonalities of pre-chronic obstructive pulmonary disease (pre-COPD) by focusing on COPD, emphysema, and chronic bronchitis. Methods Mendelian randomization was used to explore the causal relationship between gut microbiota and 9 respiratory diseases, sensitivity analysis was conducted, and robustness was verified. Single nucleotide polymorphisms of common gut microbiota were mapped to genes to explore their common mechanisms. Results Mendelian randomization studies found that 66 gut microbiota had a causal relationship with 9 respiratory diseases, and 15 gut microbiota might be potential common mechanisms for these 9 respiratory diseases, with a total of 85 potential genes. GO functional enrichment analysis found that these genes were mainly enriched in biological functions such as synaptic transmission, synaptic membrane, cytokine activity, and growth factor binding. KEGG enrichment analysis showed that these genes were mainly enriched in glutamatergic synapses, relaxin signaling pathway, calcium signaling pathway, Rap1 signaling pathway, and PI3K-Akt signaling pathway. Allisonella and Prevotellaceae might be protective factors for pre-COPD, while Howardella might be a risk factor. Ten protective genes and six risk genes for the pre-COPD were identified. Conclusion This study further confirms the correlation between the lung-gut axis and the lung-colon connection, explores the potential common mechanisms of 9 respiratory diseases, investigates the potential mechanisms of pre-COPD based on the common gut microbiota of COPD, chronic bronchitis, and emphysema, and provides some ideas for the early prevention and treatment of COPD, and diagnosis of pre-COPD from the perspective of gut microbiota.

Objective:To analyze the interaction of tissue delta-like ligand 3 (DLL3) expression and xeroderma pigmentosum gene G (XPG) gene polymorphism on the sensitivity of advanced lung squamous cell carcinoma to platinum-based chemotherapy.Methods:One hundred and forty patients with advanced squamous lung cancer admitted to Yuechi County People′s Hospital from March 2019 to December 2021 were selected and all were given carboplatin and paclitaxel for injection (albumin-bound) in a fully informed manner, with one cycle every 3 weeks for a total of 4 cycles of treatment. The patients were divided into sensitive group (46 cases) and non-sensitive group (94 cases) according to their sensitivity to chemotherapy. Baseline information, tissue DLL3 expression and XPG gene polymorphism were compared between the two groups, and tissue DLL3 expression in patients with different XPG genotypes was compared. Multi-factor Logistic regression analysis was used to analyzed the factors associated with the sensitivity to chemotherapy, and interaction coefficient γ was used to analyze tissue DLL3 expression and XPG.Results:The tissue DLL3 expression score of the sensitive group was lower than that in the non-sensitive group: (3.28 ± 0.93) scores vs. (7.59 ± 1.22) scores, there was statistical difference ( P<0.01). The patients with CC genotype in the sensitive group were more than those in the non-sensitive group, and the patients with CT and TT genotypes were less than those in the non-sensitive group ( P<0.05). Tissue DLL3 expression score in patients with CC, CT, TT genotype were (3.51 ± 0.93), (6.76 ± 1.08), (10.09 ± 1.12) scores, there was statistical difference ( P<0.05); and tissue DLL3 expression score was CC