Role of salivary glycopatterns for oral microbiota associated with gastric cancer

Microbiota in the oral cavity plays an important role in maintaining human health. Our previous studies have revealed significant alterations of salivary glycopatterns in gastric cancer (GC) patients, but it is unclear whether these altered salivary glycopatterns can cause the dysbiosis of oral microbiota. In this study, the oral microbiome of healthy volunteers (HVs) and GC patients were detected. The neoglycoproteins were then synthesized according to the altered glycopatterns in GC patients and used to explore the effects of specific salivary glycopattern against oral microbiota. The results showed that five species were significantly increased (p < 0.05) while two species were significantly decreased (p < 0.01) in the saliva of GC patients compared with that of HVs. And the fucose-neoglycoproteins (30-100 μg/mL) could reduce the adhesion and toxicity of Aggregatibacter segnis (A. segnis) to oral cells (HOEC and CAL-27), change the glycan structures of lipopolysaccharide on the surface of A. segnis, and enhance the capacity of A. segnis to trigger innate immune responses. This study revealed that the changes of salivary protein glycopatterns in GC patients might contribute to the dysbiosis of oral microbiota, and had important implications in developing new carbohydrate drugs to maintain a balanced microbiota in the oral.