Fig. 5.

Dysbiosis in OSCC. a A correlation exists between dysbiosis and the occurrence of various cancers. OSCC could be caused by Lactobacillus, Porphyomonas gingivalis, Fusobacterium nucleatum, and Prevotella intermedia. OSCC patients have elevated levels of Prevotella melanogenic, Streptococcus mitis, and Capnocytophaga gingivalis in their saliva, while Rothia, Leptotrichia, Haemophilus, Aggregatibacter, and Neisseria are diminished. b P. gingivalis stimulates the expression of B7-H1 receptors on OSCC cells. B7-H1 activates the development of Tregs, thereby inhibiting effector T cells. S. mitis has been demonstrated to trigger mutations and epithelial hyperplasia by generating acetaldehyde. OSCC oral squamous cell carcinoma, Tregs regulatory T cells