Correlation Between Tongue Coating Variation And Tongue Coating Microbiota In Preoperative Patients With Gastric Cancer

OBJECTIVE:The present study aims to investigate the correlation between the formation of tongue coating and the tongue coating flora.METHODS:A hospital-based case-control study was developed with 47 patients with gastric cancer(GC)before surgery as case and 42 healthy people as control.The tongue coating flora was measured by 454 high-throughput pyrosequencing based on 16S rRNA gene.Multi-factor correlated analysis was conducted between the tongue coating and the tongue coating flora.RESULTS:(1)The richness and diversity of the tongue coating flora didn’t correlate to the coating color or the coating nature both in the cases and controls(P>0.05).(2)There were significantly different 31 taxa(1 classes,6 orders,9 families and 14 genera)and 10 taxa(1 orders,3 families and 6 genera)between white coating and yellow coating in the cases and controls,respectively(P<0.05).However,only 5 taxa(1 order,1 family and three genera)and 2 taxa(1 family and 1 genus)were observed to be significantly different between thin coating and thick coating in the cases and controls,respectively(P<0.05).The relative abundances of Bradyrhizobiaceae and Delftia in the yellow coating were distinctly higher than that in the white coating(P<0.05).(3)The ratio of significantly negative correlations of the bacterial genera between the white coating and yellow coating was obviously higher than that in the white coating or that in the yellow coating,and similar phenomenon was observed in the tongue nature.(4)Based on the bacterial function prediction of the tongue coating,the function purine metabolism was significantly higher in GC patients with yellow coating than that with white coating(P<0.05),which was confirmed by the serum uric acid level.Meanwhile,the function lipid metabolism was stronger in the controls with thick coating than that in the controls with thin coating(P<0.05),which was confirmed by the serum total cholesterol level.CONCLUSIONS:The structure of tongue coating flora had stronger impact on the coating color than the coating nature,and the symbiotic correlation in the tongue coating flora may reflect the scientific connotation of TCM syndrome differentiation of tongue coating.