Study On Microecological Characteristics Of Tongue Coating In Patients With Chronic Obstructive Pulmonary Disease At Stable Stage Based On 16SrRNA High-throughput Sequencing

ObjectiveThis study aimed to explore the characteristics of tongue coating microecology of stable COPD by comparing the differences and similarities of tongue coating microecology between stable COPD and healthy individuals and among different coating colors in COPD patients.MethodsThirty stable COPD patients,who were looking for treatment in the First Affiliated Hospital of Anhui University of Chinese Medicine from June 2019 to September 2020,and ten healthy individuals were included in this study.The stable COPD patients were separated into yellow tongue coating group and white tongue coating group according to the color of tongue coating.The tongue coating samples of all individuals were collected and followed by sequencing using Illumina high-throughput sequencing technology,which was conducted for the species annotation and evaluation,species composition analysis,sample comparison analysis,species difference analysis,clinical factor association analysis,and functional prediction analysis.Results1.The Firmicutes,Bacteroidetes,Actinobacteria,Proteobacteria,and Fusobacteria were ranked in the top bacterial communities at the phylum level of tongue coating both in the COPD group and healthy control group.2.No statistic difference was observed in Alpha diversity between COPD group and healthy control group（P>0.05）;however,there was a significant difference in Alpha diversity of tongue microbiome between yellow tongue coating group and white tongue coating group（P<0.05）.The results of sample hierarchical cluster analysis showed that the yellow tongue coating group and the white tongue coating group were clustered in the upper and lower segments of the figure.The results of the PLS-DA analysis indicated that the composition of the two bacterial communities was different.3.By comparison of different strains between COPD group and healthy control group,the results showed that 1 class,1 order,4 families,5 genera,and 10 species were significantly different（P<0.05）,and the relative abundance of Capnocytophaga granulosa in the COPD group of which was higher than that in the healthy control group.In the case of white tongue coating group versus the yellow tongue coating group,the 3orders,5 families,11 genera,and 24 species（P<0.05）were significant differences,and Prevotella,Lachnoanaerobaculum,and Gemella of which were prominent species.4.The clinical factor association analysis showed that the relative abundance of Campylobacter was positively correlated with FEV₁%predicted value,FEV₁/FVC and CAT score of patients,Streptococcus was positively correlated with pulmonary ventilation function（FEV₁%predictive value,FEV₁/FVC）of patients,and the relative abundance of Capnocytophaga was positively correlated with CAT scores.5.The functional prediction analysis showed that the abundance of genes referred to energy production and transformation and the transportation and metabolism of nutrients like amino acids and nucleotides was high in the tongue coating microbiome.Conclusion1.There is a certain correlation between the microecological imbalance of tongue coating and the occurrence and development of the disease in patients with stable COPD,and Capnocytophaga and Campylobacter may be the microbial markers of stable COPD.2.Biodiversity of tongue coating microbiome in stable COPD patients with different coating colors was different.Gemella,Lachnoanaerobaculum,and several Prevotella species may be contributed to the formation of different tongue coating colors.