A Prospective Observational Study Analyzing the Diversity and Specific Composition of the Oral and Gut Microbiota in...

Host microbiota dysbiosis has been recognized as a key factor in lung cancer. However, the specific diversity and composition of microbiota in lung cancer patients remain unknown. This single-center prospective observational study analyzed both saliva and fecal samples from 74 participants [lung cancer (LC) patients: n=53; lung inflammation (LI) patients: n=11; healthy control (HC): n=10].

We performed 16S ribosomal RNA gene sequencing and analyzed the associations between oral and gut microbiota diversity and composition across the three groups.

Alpha diversity of the oral microbiota was significantly lower in the LC group than in the HC group (Chao 1, p=0.004; Simpson, p=0.018; Shannon, p=0.009). Beta diversity of both oral and gut microbiota showed significant differences among the three groups (PERMANOVA, oral: p=0.005; gut: p=0.002). Compositional differences in the oral microbiota were observed between the HC and LC or LI groups; in particular, Bacilli class, Streptococcaceae family, Streptococcus genus, Firmicutes phylum, and Lactobacillales order were more abundant in the LC group. Additionally, six oral-related microbiota showed significant abundance in the gut of the LC group (p=0.00182).

The oral microbiota in lung cancer patients is significantly different from that in healthy individuals. Specific changes in oral microbiota and oral-related gut microbiota compositions were evident in lung cancer patients. These findings might be useful for identifying novel biomarkers to predict the risk of lung cancer and prevent the disease.