Microbiological characteristics of different tongue coatings in adults

Abstract

Background Tongue coating is an important health indicator in traditional Chinese medicine (TCM). The tongue coating microbiome can distinguish disease patients from healthy controls. To study the relationship between different types of tongue coatings and health, we analyzed the species composition of different types of tongue coatings and the co-occurrence relationships between microorganisms in Chinese adults. From June 2019 to October 2020, 158 adults from Hangzhou and Shaoxing City, Zhejiang Province, were enrolled. We classified the TCM tongue coatings into four different types: thin white tongue fur (TWF), thin yellow tongue fur (TYF), white greasy tongue fur (WGF), and yellow greasy tongue fur (YGF). Tongue coating specimens were collected and used for 16S rRNA gene sequencing using the Illumina MiSeq system. Wilcoxon rank-sum and permutational multivariate analysis of variance tests were used to analyze the data. The microbial networks in the four types of tongue coatings were inferred independently using sparse inverse covariance estimation for ecological association inference. Results The microbial composition was similar among the different tongue coatings; however, the abundance of microorganisms differed. TWF had a higher abundance of Fusobacterium periodonticum and Neisseria mucosa, the highest α-diversity, and a highly connected community (average degree = 3.59, average closeness centrality = 0.33). TYF had the lowest α-diversity, but the most species in the co-occurrence network diagram (number of nodes = 88). The platelet-to-lymphocyte ratio (PLR) was associated with tongue coating (P = 0.035), and the YGF and TYF groups had higher PLR values. In the co-occurrence network, Aggregatibacter segnis was the “driver species” of the TWF and TYF groups and correlated with C-reactive protein (P < 0.05). Streptococcus anginosus was the “driver species” in the YGF and TWF groups and was positively correlated with body mass index and weight (P < 0.05). Conclusion Different tongue coatings have similar microbial compositions but different abundances of certain bacteria. The co-occurrence of microorganisms in the different tongue coatings also varies. The significance of different tongue coatings in TCM theory is consistent with the characteristics and roles of the corresponding tongue-coating microbes. This further supports considering tongue coating as a risk factor for disease.

A survey of artificial intelligence in tongue image for disease diagnosis and syndrome differentiation

“…Second, there are many tongue image feature types, as shown in Figure 1 , and they are more likely to be comprehensively judged as the probability of a certain type of health state. 10 , 121 The health state abstracted from the whole body system is related to the concept of “syndrome.” TCM theory believes that the human body is an interrelated system, the running state and abnormal symptoms of different body parts are interrelated and mutually affected, 1 , 122 showing a certain distribution law, and syndrome types could be treated as the clusters summarized by this distribution. Therefore, not only do the features of the tongue image need to be integrated but also the features from other diagnostic methods, to better distinguish syndromes.…”

“…TCM physicians rely heavily on it as they obtain the whole human health state through it, so they arrange the herbs to balance the body's health state. Because of the abundant superficial vascular tissue, the tongue can transmit many useful signals in real time, 1 – 3 which may indicate important medical information. Nowadays, tongue diagnosis can even be used for disease prediction or disease stage estimation.…”

Oral microbiome as a co-mediator of halitosis and periodontitis: a narrative review

“…In studies examining tongue-coating microbes, fusobacterium periodonticum , neisseria mucosa , and aggregatibacter segnis were associated with tongue coating ( 86 ). The Extended Human Oral Microbiome Database (eHOMD) was updated in 2017 and found that six major phyla including Firmicutes , Actinobacteria , Proteobacteria , Fusobacteria , Bacteroidetes and Spirochetes , constitute 96% of total oral bacteria ( 87 ).…”