Progress of Research on the Relationship between Lung Microbiome and Lung Cancer / 中国肺癌杂志

The microbiota plays an important role in the biological functions of the human body and is associated with various disease states such as inflammation (gastritis, hepatitis) and cancer (stomach, cervical, liver). The Human Microbiome Project painted a panorama of human microorganisms in its first phase, incorporating body parts such as the nasal cavity, oral cavity, intestine, vagina and skin, while the lungs were considered a sterile environment. However, studies in recent years have confirmed the presence of a rich microbial community in the lung, and the association of this lung microbiota with lung disease has become a hot topic of research. Current research has found that patients with lung cancer have a specific microbiota compared to healthy individuals or patients with lung disease. Even in patients with lung cancer, a lung microbiota specific to the tumor site is present. In addition, different pathological types and metastatic status of lung cancer can lead to differences in microbiota. Mechanistic studies have found that the lung microbiota may influence lung cancer development by affecting the immune response. Clinical studies on lung microbiota and immunotherapy are still in the preliminary stage. More relevant studies are needed in the future to provide high-quality evidence to further understand the oncogenic mechanisms of lung microbiota and provide new ideas for clinical treatment. This paper briefly reviews the progress of lung microbiota research in terms of its relevance to lung cancer, possible molecular mechanisms and applications in clinical treatment, and provides an outlook for future research.
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Changes of lung microbiome of acute respiratory distress syndrome before and after treatment under open airway / 中华危重病急救医学

Objective:To analyze the differences and similarities of pre-treatment and post-treatment lung microbiome of acute respiratory distress syndrome (ARDS) and find out the change rules of the lung microbiome in the progression of ARDS according to different prognosis.Methods:A retrospective study was conducted. Patients with ARDS caused by severe pneumonia admitted to intensive care unit (ICU) of Jiangmen Central Hospital from February 2019 to January 2020 were enrolled as the study subjects. The patients were divided into pre-treatment (ARDS-preT) group (24 cases), post-treatment survival (ARDS-poT-Survival) group (17 cases), and post-treatment death (ARDS-poT-Dead) group (7 cases). ICU patients with mild pulmonary infection and non-ARDS admitted to ICU during the same period were enrolled as control group (25 cases). The similarities and differences of lung microbiome in four groups were analyzed and compared, and the possible pathogenic bacteria (potential risk factors for death) and probiotics (potential survival and protective factors) related to death caused by ARDS were screened.Results:In terms of pathogenic microorganisms, the positive rates of Escherichia coli and Candida albicans in the ARDS-poT-Dead group were significantly higher than those in the ARDS-poT-Survival group [57.1% (4/7) vs. 5.9% (1/17) and 57.1% (4/7) vs. 0% (0/7), both P < 0.05]. In the screening of background bacteria, the decrease of bacteria in the ARDS-preT group compared with the ARDS-poT-Survival group, the ARDS-poT-Dead group compared with the ARDS-poT-Survival group, the ARDS-poT-Dead group compared with the control group, the reduced bacteria might be pulmonary probiotics (potential protective factor for ARDS). The screening result was Hydrobacter [ARDS-preT group vs. ARDS-poT-Survival group: 62.5% (15/24) vs. 94.1% (16/17); ARDS-poT-Dead group vs. ARDS-poT-Survival group: 14.3% (1/7) vs. 94.1% (16/17); ARDS-poT-Dead vs. control: 14.3% (1/7) vs. 96.0% (24/25), all P < 0.05]. In the screening of background bacteria, the increase of bacteria in the ARDS-poT-Dead group compared with the ARDS-preT group, the ARDS-poT-Dead group compared with the ARDS-poT-Survival group, the ARDS-poT-Dead group compared with the control group, and the increased bacteria might be potential pulmonary pathogen (potential risk factor for death of ARDS), which belonged to Enterobacteria: Edwardsiella, Enterobacteriaceae, Escherichia, Klebsiella, Kluyvera, Lelliottia, Pantoea, Raoultella. Conclusions:The results revealed the increase of Escherichia coli or Candida albicans in pulmonary pathogenic microorganisms, or the increase of Enterobacteria in background bacteria may be the risk factors for the death of ARDS. Additionally, background bacteria Hydrobacter probably is a protective factor for the survival of ARDS. Whether it can be used as a novel treatment for ARDS is worth further investigation.

The lower respiratory tract microbiome in pediatric patients with ventilator-associated pneumonia / 中国小儿急救医学

Ventilator associated pneumonia(VAP)is one of the major source of nosocomial infection in PICU, of which the pathogenesis remains unclear.Recent metataxonomic and metagenomic technologies, from 16S ribosomal RNA to whole genome sequencing, have revealed that healthy lungs harbor a dynamic ecosystem of bacteria and dysbiosis of the respiratory microbiome involved in the pathogenesis and progression of VAP.Recent studies have illustrated that the imbalance of species diversity and abundance of lung microbiome might be the underlying cause of VAP through regulating local mucosal immune response.These methods offer the potential to better interrogate the relationship between an intubated individual′s respiratory microbiota and the underlying disease process to provide important insights into the pathogenesis of VAP, optimizing disease surveillance and multi-drug resistant microbes detection.

Effects of inhaling vehicle exhaust on lung microbiome in mice / 上海交通大学学报（医学版）

Objective·To observe the changes of hmg tissue and lung microbiome in mice after inhalation of vehicle exhaust,and to assess the impact of air pollution caused by vehicle exhaust on the respiratory system of the population.Methods· Ten C57BL/6 mice were divided into experimental group and control group randomly.Experimental group was inflicted with continuous exposure to automobile exhaust for 5 d (1 h/d),while the control group was exposed to clean air.After a 5-day of environmental exposure,the lung microbial composition was analyzed by 16S rRNA pyrosequencing and the structure of the lung tissue was assessed by histological analysis.Results· There was no significant difference in pathological changes of lung tissue between the experimental group and the control group.However,there were significant differences in the composition and abundance of bacteria in the experimental and control groups.At the phylum level,comparing with the control group the Firmicutes was significantly increased in the experimental group,while the Bacteroidetes and Proteobacteria were significantly reduced.At the genus level,the increase of the Firmicutes was mainly related to the increase of the Coprococcus.The reduction of the Bacteroidetes was related to the reduction of Cytophaga while the reduction of the Proteobacteria was related to three main strains namely Ochrobactrum,Methylobacterium and Acinetobacter.Amycolatopsis was also reduced significantly.Conclusion-Short-term exposure to vehicle exhaust conditions changes the species composition and abundance of lung microbiome in mice,but no lung tissue lesions were observed.

Effects of inhaling vehicle exhaust on lung microbiome in mice / 上海交通大学学报（医学版）

Objective: To observe the changes of lung tissue and lung microbiome in mice after inhalation of vehicle exhaust, and to assess the impact of air pollution caused by vehicle exhaust on the respiratory system of the population. Methods: Ten C57BL/6 mice were divided into experimental group and control group randomly. Experimental group was inflicted with continuous exposure to automobile exhaust for 5 d (1 h/d), while the control group was exposed to clean air. After a 5-day of environmental exposure, the lung microbial composition was analyzed by 16S rRNA pyrosequencing and the structure of the lung tissue was assessed by histological analysis. Results: There was no significant difference in pathological changes of lung tissue between the experimental group and the control group. However, there were significant differences in the composition and abundance of bacteria in the experimental and control groups. At the phylum level, comparing with the control group the Firmicutes was significantly increased in the experimental group, while the Bacteroidetes and Proteobacteria were significantly reduced. At the genus level, the increase of the Firmicutes was mainly related to the increase of the Coprococcus. The reduction of the Bacteroidetes was related to the reduction of Cytophaga while the reduction of the Proteobacteria was related to three main strains namely Ochrobactrum, Methylobacterium and Acinetobacter. Amycolatopsis was also reduced significantly. Conclusion: Short-term exposure to vehicle exhaust conditions changes the species composition and abundance of lung microbiome in mice, but no lung tissue lesions were observed.