Clinical factors associated with composition of lung microbiota and important taxa predicting clinical prognosis in patients with severe community-acquired pneumonia / 医学前沿

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia (SCAP). We prospectively enrolled consecutive SCAP patients admitted to ICU. Bronchoscopy was performed at bedside within 48 h of ICU admission, and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage fluid. The primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following bronchoscopy. Sixty-seven patients were included. Multivariable permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota (R2 = 0.033; P = 0.018), followed by acute kidney injury (AKI; R2 = 0.032; P = 0.011) and plasma MIP-1β level (R2 = 0.027; P = 0.044). Random forest identified that the families Prevotellaceae, Moraxellaceae, and Staphylococcaceae were the biomarkers related to the positive bacteria lab test results. Multivariable Cox regression showed that the increase in α-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical improvements. The positive bacteria lab test results, AKI, and plasma MIP-1β level were associated with patients' lung microbiota composition on ICU admission. The families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements.

Microbiota pulmonar y el eje intestino-pulmón

RESUMEN Introducción: A la luz de los conocimientos más recientes, es trascendente enfatizar el potencial papel que desarrolla la microbiota intestinal, a través del eje intestino-pulmón, con la microbiota pulmonar. Objetivo: Actualizar criterios acerca de la microbiota pulmonar en sujetos sanos y su relación con el eje intestino-pulmón. Métodos: Se revisaron publicaciones en español e inglés en PubMed, Google Scholar, ScIELO, desde enero 2010-mayo 2020, se usaron los términos: microbiota pulmonar, microbiota vías respiratorias inferiores, eje intestino-pulmón, microbiota pulmonar e inmunidad y probióticos de nueva generación. Análisis e integración de la información: Se exponen argumentos relacionados con la presencia de microbiota comensal residente en el pulmón formada por bacterias, hongos y virus como integrantes de la comunidad microbiana. Papel del eje intestino-pulmón y su participación en modulación inmune. Se describen rasgos de la microbiota pulmonar, su biomasa, diversidad, y filos integrantes. Se resumen investigaciones en animales. Se destaca valor de la nueva tecnología de secuenciación gen 16S del ARNr para estudio e identificación. Consideraciones finales: El pulmón era considerado órgano estéril. Aquí se documenta la presencia de microbiota comensal residente en el pulmón, de gran diversidad, se postulan los mecanismos del eje intestino-pulmón y su papel en la modulación de la inmunidad pulmonar y valor diagnóstico en enfermedades del tracto respiratorio inferior. Se enfatiza el uso futuro de probióticos de nueva generación como moduladores de la microbiota pulmonar.

ABSTRACT Introduction: In the light of the most recent knowledge, it is important to emphasize the potential role played by the gut microbiota, through the gut-lung axis, with the lung microbiota. Objective: Update the criteria about the lung microbiota in healthy subjects and its relationship with the gut-lung axis. Methods: Publications in Spanish and English were reviewed in PubMed, Google Scholar, ScIELO, from January 2010 to May 2020; the following terms were used: lung microbiota, lower respiratory tract microbiota, gut-lung axis, lung microbiota and immunity and next- generation probiotics. Analysis and integration of information: Arguments related to the presence of commensal microbiota resident in the lung formed by bacteria, fungi and viruses as members of the microbial community are presented. Role of the gut-lung axis and its participation in immune modulation. Features of the lung microbiota, its biomass, diversity, and component phylums are described. Researches in animals are summarized. The value of the new 16S gene sequencing technology of rRNA for study and identification is highlighted. Final considerations: The lung was considered a sterile organ. Here the presence of resident commensal microbiota of great diversity in the lung is documented; the mechanisms of the gut-lung axis and its role in the modulation of lung immunity and diagnostic value in diseases of the lower respiratory tract are stated. The future use of next-generation probiotics as modulators of the lung microbiota is emphasized.

Lung and gut microbiota and their interaction with the carcinogenesis and development of lung cancer: a review / 生物工程学报

Lung microbiota and gut microbiota are closely related to lung cancer. Studies have shown that the dysbiosis, i.e., the significantly altered composition and structure of gut and lung microbiota, usually occurs in patients with lung cancer. With the introduction of "Gut-Lung Axis", an increasing attention has been paid to the close relationship between the lung and gut microbiota in human body. A deeper insight into this relationship would facilitate understanding the mechanisms behind the carcinogenesis and development of lung cancer. This article summarizes the composition of lung and gut microbiota in patients with lung cancer and the possible interaction mechanisms, highlighting the importance of the immune system in the Gut-Lung Axis. The effects of lung and gut microbiota on the clinical treatment of lung cancer were summarized, based on which the authors propose that the lung and gut microbiota can be used as novel targets for early diagnosis and treatment of lung cancer.