Description of histologically normal lung tissue microbiota and its epidemiological and clinical relevance
Friday, September 18, 2015 — Poster Session V
- G Yu
- M Gail
- N Caporaso
- J Ravel
- MT Landi
Little is known about microbial communities (microbiota) in human histologically normal lung tissue. We describe diversity and structure (both taxonomy and function) of lung microbiota of normal lung tissues from lung cancer patients and report on associations with epidemiologic and clinical characteristics. We sequenced bacterial 16s rRNA gene by MiSeq platform from 165 histologically normal lung tissue samples and 31 tumor samples. Compared to previously studied body sites (including oral and nasal cavity, vagina, skin, and stool), histologically normal lung microbiota had distinct taxonomical and functional profiles. It was enriched with Proteobacteria (60%) and Thermi (9%), and had higher functional prevalence of amino acid metabolism and xenobiotic biodegradation and metabolism. Our results showed that increased air pollution (particulate matter PM10) was significantly associated with increased phylogenetic diversity and decreased Proteobacteria prevalence. Normal samples from late stage patients (IIIB, IV) had significant higher phylogenetic diversity than normal samples from early stage patients (IA to IIIA). Normal samples from patients with a history of bronchitis had significant lower phylogenetic diversity than normal samples from patients without a history of bronchitis. Our results also showed significant differences in microbiota between tumor and normal samples. Normal samples had significantly higher phylogenetic diversity than tumor samples. squamous carcinoma and adenocarcinoma differed significantly in phylogenetic diversity in tumor samples. In conclusion, our study reported on human lung microbial diversity and structure in a large sample of histologically normal tissues, and suggested associations with air pollution and lung diseases such as bronchitis and lung cancer.