Airway microbial communities, smoking and asthma in a general population sample

Abstract

Background Normal airway microbial communities play a central role in respiratory health but are poorly characterized. Cigarette smoking is the dominant global environmental influence on lung function, and asthma has become the most prevalent chronic respiratory disease worldwide. Both conditions have major microbial components that are incompletely defined. Methods We investigated airway bacterial communities in a general population sample of 529 Australian adults. Posterior oropharyngeal swabs were analyzed by sequencing of the 16S rRNA gene. The microbiota were characterized according to their prevalence, abundance and network memberships. Findings The microbiota were similar across the general population, and were strongly organized into co-abundance networks. Smoking was associated with diversity loss, negative effects on abundant taxa, profound alterations to network structure and expansion of Streptococcus spp. By contrast, the asthmatic microbiota were selectively affected by an increase in Neisseria spp. and by reduced numbers of low abundance but prevalent organisms. Interpretation Our study shows that the healthy airway microbiota in this population were contained within a highly structured ecosystem, suggesting balanced relationships between the microbiome and human host factors. The marked abnormalities in smokers may contribute to chronic obstructive pulmonary disease (COPD) and lung cancer. The narrow spectrum of abnormalities in asthmatics encourages investigation of damaging and protective effects of specific bacteria. Funding The study was funded by the Asmarley Trust and a Wellcome Joint Senior Investigator Award to WOCC and MFM (WT096964MA and WT097117MA). The Busselton Healthy Ageing Study is supported by the Government of Western Australia (Office of Science, Department of Health) the City of Busselton, and private donations.

Informatic analysis of the pulmonary microecology in non-cystic fibrosis bronchiectasis at three different stages

“…The interactions among bacterial genera are extremely subtle. According to previous studies [ 30 , 31 ], the abundances of Prevotella and Veillonella significantly increase in the pulmonary microecology of patients with lung cancer and those with asthma [ 28 , 29 ]. This study found that Prevotella and Veillonella cooperated with each other and that Ochrobactrum and Rhodococcus were synergetic.…”

“…The interrelations among the bacteria suggest a hypothesis: in addition to the use of drugs to suppress or kill pathogenic bacteria, it means to increase the abundance of the competitor of the pathogenic bacteria, such as bacterial transplantation and regulation of the intestinal flora, may also help enhance the treatment effect. Oral administration or transplantation of probiotics can improve pulmonary resistance against viruses, Mycobacterium tuberculosis , and other pathogenic bacteria [ 30 , 31 , 32 , 33 , 34 ]. Currently, broad- or ultrabroad-spectrum antibiotics have been used to target Pseudomonas aeruginosa in clinical practice [ 35 , 36 , 37 , 38 ].…”

Impact of Lung Microbiota on COPD

“…The incidence of COPD has increased worldwide, and it is the principal cause of morbidity and mortality [ 2 ]. The common symptoms of the disease include dyspnoea, cough, sputum, and altered respiratory composition resulting from chronic exposure to cigarette smoke (CS) or pollutants [ 3 ]. In fact, CS affects the microbial composition mainly through lack of oxygen and increased formation of bacterial biofilms [ 3 , 4 ].…”

“…The common symptoms of the disease include dyspnoea, cough, sputum, and altered respiratory composition resulting from chronic exposure to cigarette smoke (CS) or pollutants [ 3 ]. In fact, CS affects the microbial composition mainly through lack of oxygen and increased formation of bacterial biofilms [ 3 , 4 ]. Inhalation of CS results in the activation of epithelial and immunomodulatory cells, including neutrophils, macrophages, and T cells [ 5 ].…”

“…The respiratory tract is one of the main entrances for microorganisms into the human body; thus, it plays a key role in the composition of the microbiota. The airway microbiota is finely organised, building a protective environment for the host and a hostile condition for pathogenic agent colonisation, ensuring a balanced relationship between microbiota and human host signals [ 3 ]. Inhaled microorganisms find the ideal habitat to develop in the lung, and they are also able to reduce factors that regulate their elimination.…”