Study On Characterization Of Lung And Oral Microbiota In Lung Cancer Patients

BackgroundLung cancer is a highly lethal malignancy with morbidity and mortality rates worldwide,with two pathological types:non-small cell lung cancer(NSCLC)and small-cell lung cancer(SCLC),of which NSCLC is the predominant,and the most common pathological subtypes in NSCLC are adenocarcinoma and squamous carcinoma.Existing treatmenthave limited impact on overall survival,and there is a need for new approaches.Human microbiomes have been shown to impact tumorigenesis and tumor efficacy.However,the relationship between lung microbiota changes and lung cancer is understudied,and there is a lack of in vitro cultured strain collections for further studies.Additionally,the connection between oral flora changes and lung cancer is not well understood.Therefore,it is very important to explore the potential drivers in the development of lung cancer from a microbiota dimension to show the significance.In this study,we investigate the diversity and composition of the microbiota in brochoalveolar lavage fluid,lung cancer tissues,and oral sites of lung cancer patients.We also explore the correlation between lung and oral microbiomes and biomarkers for lung cancer diagnosis.In addition,a lung and oral microbial biobank from lung cancer patients is established,which represents a useful resource for studies of host-microbe interactions.ObjectiveThe objectives of this study are to compare and characterize the lung and oral cavity microbiota of lung cancer patients,to isolate and cultivate lung microbiota from human lungs and lung cancer tissues,and to isolate bacterial pathobionts from lung cancer patients for further validation experiments.MethodsThe study examined the pneumonic and oral microbiota of lung cancer patients using culturomics and 16S r DNA sequencing,and applied the culturomics approach to cancer tissue specimens and characterized the lung cancer tissue microbiota by 16S r DNA amplicon sequencing.The R statistical programming language was used to analyze the differences in the diversity and composition of the lung and oral flora of lung cancer patinets.The obtained strains were validated for relevance to lung cancer disease.A549 was infected with supernatant of bacteria cultured from lung cancer tissues and the normalized cell index was determined by RTCA.ELISA was employed to detect the secretion levels of inflammatory factors(TNF-α、IL-6,and IL-1β)in the cell culture supernatants.The potential new strains were identified by morphological,physiological and biochemical characteristics,chemical classification,and genetic characteristics.ResultsThe study found alterations in the microbial community of patients with lung cancer,whose diversity might be site and pathology dependent.Using culturomics,the study found that Streptococcus and Veillonella were highly dominant in both pneumonic and oral samples of patients with lung cancer,suggesting the possible deleterious effects of airway microbial dysbiosis originating from the oral cavity.The study also showed that Prevotella oralis was isolated only from the H group,which was consistent with the findings of 16S r DNA sequencing.A total of 12 identified bacteria were cultured and identified.The cultured strains did not affect cellular proliferation but enhanced the levels of proinflammatory factors to mediate the tumor microenvironment.The multiphasic analysis of SWB101512 and SWB19611 confirmed that they were a new taxon in the Eggerthellace family,named Curtanaerobium respiraculi,SWB101512~T(=GDMCC 1.2991~T=JCM 35330~T).ConclusionThis study suggests potential bacterial biomarkers and new targets for lung cancer diagnosis and treatment.The study isolated strains that can be used to explore causative relationships in lung cancer development.The study also identified a certain amount of unclassified bacterial resources in human lungs,and new bacterial species with new characteristics can be identified from human lungs.