Associations of oral and intestinal florae and serum inflammatory factors with pathogenesis of oral cancer.

Abstract

The aim of this study was to explore the effects of oral and intestinal florae and serum inflammatory factors on the pathogenesis of oral cancer. Oral cancer patients and healthy subjects in our hospital were enrolled in disease group (n=50) and control group (n=50), respectively. Oral flora of subjects was collected using the sterile cotton swab. Microbial deoxyribonucleic acid (DNA) was extracted for Polymerase Chain Reaction (PCR) amplification and sequencing. Subsequently, the feces were also collected from patients, and sent to the company for analysis of microbial composition via sequencing. In addition, the levels of serum inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), IL-6, and IL-1β in disease group and control group were detected via enzyme-linked immunosorbent assay (ELISA). The number of patients with a history of drinking (p=0.040) and betel nut chewing (p=0.000) in the disease group was larger than that in the control group, and the difference was statistically significant. In terms of oral flora distribution, the ratios of dominant bacteria Staphylococcus and Rothia were 64% and 50% in disease group, which were significantly higher than those in the control group (24% and 18%) (p=0.023 and 0.034). In terms of intestinal flora distribution, the abundance of intestinal florae (Flavobacteriaceae, Sphingobacteriales, Rikenella, Pseudomonadales, Tetragenococcus and Acinetobacter) in the disease group was remarkably higher than that in the control group (p<0.05). However, the abundance of Vagococcus and Pediococcus in control group was significantly higher than that in the disease group (p<0.05). Among intestinal flora, Firmicutes exhibited a highly positive correlation with Bacteroides (r=0.341, p=0.023), and a highly negative correlation with Ruminococcus (r=-0.832, p=0.000). Bacteroides had a highly negative correlation with Lactobacillus (r=-0.763, p=0.000) and Enterococcus (r=-0.461, p=0.000). In disease group, the levels of TNF-α (p=0.021), IL-8 (p=0.000), and IL-1β (p=0.000) were evidently higher than those in the control group [(23.51±2.14) ng/L vs. (12.34±2.45) ng/L, (89.75±4.29) ng/L vs. (43.23±3.25) ng/L, (42.25±3.25) ng/L vs. (15.32±1.47) ng/L]. However, there was no statistically significant difference in IL-6 level between the two groups (p=0.217). Oral and intestinal florae and serum inflammatory factors are associated with the pathogenesis of oral cancer.