Advanced Search

Journal of Traditional Chinese Medicine >

2026 , Vol. 46 >Issue 2: 501 - 508

DOI: https://doi.org/10.19852/j.cnki.jtcm.2026.02.021

Reviews

Tongue-coating microbiome as a predictor of solid tumors: an updated scoping review of clinical studies

  • LI Kexin ,
  • YANG Jinzu ,
  • XIAO Kunlin ,
  • DUAN Shaojie ,
  • XIAO Kunmin
Expand
  • 1 Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
    2 Department of Oncology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
    3 Department of Emergency, Zhongshan Hospital, Fudan University, Shanghai 200030, China
    4 Department of Geriatrics, Taizhou Central Hospital, Taizhou 318000, China

LI Kexin and YANG Jinzu are co-first authors and contributed equally to this work

XIAO Kunmin, Department of Oncology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China. 20170931602@bucm.edu.cn;
DUAN Shaojie, Department of Geriatrics, Taizhou Central Hospital, Taizhou 318000, China. 1782802171@qq.com; Telephone: +86-18801020572

Received date: 2024-12-25

  Accepted date: 2025-06-20

  Online published: 2026-04-04

Fold

Abstract

This study explores the potential of tongue coating microbiota as a non-invasive biomarker for cancer and precancerous lesions by integrating insights from multi-omics technologies and Traditional Chinese Medicine (TCM) tongue diagnosis. By bridging modern molecular research with TCM diagnostic principles, this study systematically reviewed the relationship between tongue microbiota and oncological conditions, identifying 18 eligible studies through searches in PubMed, Embase, and Web of Science. The analysis reveals significant differences in microbial diversity, abundance, metabolic pathways, and functional characteristics, which enable the partial differentiation of cancer patients from healthy individuals. However, existing research remains constrained by limited sample sizes, inconsistent analytical approaches, and a lack of integrated multi-dimensional datasets. This review highlights the promising diagnostic potential of the tongue coating microbiota in cancer detection, while suggesting that future studies should focus on standardizing methodologies and employing integrated multi-omics approaches to elucidate underlying mechanisms and advance clinical applications.

Key words： tongue coating microbiota; tongue diagnosis; non-invasive biomarkers; solid tumors; review

Cite this article

LI Kexin , YANG Jinzu , XIAO Kunlin , DUAN Shaojie , XIAO Kunmin . Tongue-coating microbiome as a predictor of solid tumors: an updated scoping review of clinical studies[J]. Journal of Traditional Chinese Medicine, 2026 , 46(2) : 501 -508 . DOI: 10.19852/j.cnki.jtcm.2026.02.021

References

1. He C, Liao Q, Fu P, et al. Microbiological characteristics of different tongue coatings in adults. BMC Microbiol 2022; 22: 214.
2. Zhang Y, Zhao H, Guo Y, et al. Relationship between thick or greasy tongue-coating microbiota and tongue diagnosis in patients with primary liver cancer. Front Microbiol 2022; 13: 903616.
3. du Toit DF. The tongue: structure and function relevant to disease and oral health. SADJ 2003; 58: 375-76, 380-3.
4. Bernardi S, Zeka K, Mummolo S, et al. Development of a new protocol: a macroscopic study of the tongue dorsal surface. Ital J Anat Embryol 2013; 118: 1.
5. Seerangaiyan K, Juch F, Winkel E. Tongue coating: Its characteristics and role in intra-oral halitosis and general health: a review. J Breath Res 2017; 12: 034001.
6. Liu M, Wang X, Wu F, et al. Variations of oral microbiome in chronic insomnia patients with different tongue features. Am J Chin Med 2020; 48: 923-44.
7. Liu Q, Shi K, Bai Y, et al. Biology of tongue coating in different disease stages of RA and its value in disease progression. Microb Pathog 2024; 191: 106644.
8. Zhao Y, Gou XJ, Dai JY, et al. Differences in metabolites of different tongue coatings in patients with chronic hepatitis B. Evid Based Complement Alternat Med 2013; 2013: 204908.
9. Chen J, Sun Y, Li J, et al. In-depth metaproteomics analysis of tongue coating for gastric cancer: A multicenter diagnostic research study. Microbiome 2024; 12: 6.
10. Xu S, Xiang C, Wu J, et al. Tongue coating bacteria as a potential stable biomarker for gastric cancer independent of lifestyle. Dig Dis Sci 2021; 66: 2964-80.
11. Xu J, Xiang C, Zhang C, et al. Microbial biomarkers of common tongue coatings in patients with gastric cancer. Microb Pathog 2019; 127: 97-105.
12. Wu J, Xu S, Xiang C, et al. Tongue coating microbiota community and risk effect on gastric cancer. J Cancer 2018; 9: 4039-48.
13. Hu J, Han S, Chen Y, et al. Variations of tongue coating microbiota in patients with gastric cancer. Biomed Res Int 2015; 2015: 173729.
14. Chen Q, Lin F, Li W, et al. Distinctive lipid characteristics of colorectal cancer revealed through non-targeted lipidomics analysis of tongue coating. J Proteome Res 2024; 23: 2054-66.
15. Chen Q, Huang X, Zhang H, et al. Characterization of tongue coating microbiome from patients with colorectal cancer. J Oral Microbiol 2024; 16: 2344278.
16. Han S, Chen Y, Hu J, et al. Tongue images and tongue coating microbiome in patients with colorectal cancer. Microb Pathog 2014; 77: 1-6.
17. Ali Mohammed MM, Al Kawas S, Al-Qadhi G. Tongue-coating microbiome as a cancer predictor: a scoping review. Arch Oral Biol 2021; 132: 105271.
18. Hao Y, Zhang R, Morris R, et al. Metabolome and microbiome alterations in tongue coating of gastric precancerous lesion patients. Expert Rev Gastroenterol Hepatol 2021; 15: 949-63.
19. Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for systematic reviews and Meta-analyses: the PRISMA statement. PLoS Med 2009; 6: b2535.
20. Arksey H, O'Malley L. Scoping studies: towards a methodological framework. Int J Soc Res Methodol 2005; 8: 19-32.
21. Chen Y, Li C, Wang X, et al. Oral microbiota distinguishes patients with osteosarcoma from healthy controls. Front Cell Infect Microbiol 2024; 14: 1383878.
22. Cui J, Cui H, Yang M, et al. Tongue coating microbiome as a potential biomarker for gastritis including precancerous cascade. Protein Cell 2019; 10: 496-509.
23. He S, Sun Y, Sun W, et al. Oral microbiota disorder in GC patients revealed by 2b-RAD-M. J Transl Med 2023; 21: 831.
24. Lu H, Ren Z, Li A, et al. Tongue coating microbiome data distinguish patients with pancreatic head cancer from healthy controls. J Oral Microbiol 2019; 11: 1563409.
25. Lu H, Ren Z, Li A, et al. Deep sequencing reveals microbiota dysbiosis of tongue coat in patients with liver carcinoma. Sci Rep 2016; 6: 33142.
26. Jiang Z, Wang J, Qian X, Zhang Z, Wang S. Oral microbiota may predict the presence of esophageal squamous cell carcinoma. J Cancer Res Clin Oncol 2023; 149: 4731-9.
27. Xiao P, Hua Z, Kang X, et al. Influence of oral intaking habit on tongue coating microbiota in patients with esophageal precancerous lesions. J Cancer 2022; 13: 1168-80.
28. Jain V, Baraniya D, El-Hadedy DE, et al. Integrative metatranscriptomic analysis reveals disease-specific microbiome-host interactions in oral squamous cell carcinoma. Cancer Res Commun 2023; 3: 807-20.
29. Gordon DF Jr, Gibbons RJ. Studies of the predominant cultivable micro-organisms from the human tongue. Arch Oral Biol 1966; 11: 627-32.
30. Yokoi A, Maruyama T, Yamanaka R, et al. Relationship between acetaldehyde concentration in mouth air and tongue coating volume. J Appl Oral Sci 2015; 23: 64-70.
31. Jo R, Nishimoto Y, Umezawa K, et al. Comparison of oral microbiome profiles in stimulated and unstimulated saliva, tongue, and mouth-rinsed water. Sci Rep 2019; 9: 16124.
32. Guo XJ, Jiang T, Ma XX, et al. Relationships between diurnal changes of tongue coating microbiota and intestinal microbiota. Front Cell Infect Microbiol 2022; 12: 813790.
33. Zeng X, Jin H, Wang C, et al. Establishment of a standard tongue coating collection method for microbiome studies. Biopreserv Biobank 2023; 21: 599-609.
34. Browne HP, Forster SC, Anonye BO, et al. Culturing of 'unculturable' human microbiota reveals novel taxa and extensive sporulation. Nature 2016; 533: 543-6.
35. Forster SC, Kumar N, Anonye BO, et al. A human gut bacterial genome and culture collection for improved metagenomic analyses. Nat Biotechnol 2019; 37: 186-92.
36. Chen Z, Trivedi HM, Chhun N, et al. Using DGGE and 16S rRNA gene sequence analysis to evaluate changes in oral bacterial composition. Chin J Dent Res 2011; 14: 95-103.
37. Sano H, Wakui A, Kawachi M, et al. Profiling system of oral microbiota utilizing polymerase chain reaction-restriction fragment length polymorphism analysis. J Oral Biosci 2021; 63: 292-97.
38. Henriques AC, De Marco P. Simple protocol for molecular fingerprinting of human oral microbiota samples in lab classes. J Microbiol Biol Educ 2018; 19: 19.1.1.
39. Huang Y, Sheth RU, Zhao S, et al. High-throughput microbial culturomics using automation and machine learning. Nat Biotechnol 2023; 41: 1424-33.
40. Wang X, Howe S, Deng F, Zhao J. Current applications of absolute bacterial quantification in microbiome studies and decision-making regarding different biological questions. Microorganisms 2021; 9: 1797.
41. Galazzo G, van Best N, Benedikter BJ, et al. How to count our microbes? The effect of different quantitative microbiome profiling approaches. Front Cell Infect Microbiol 2020; 10: 403.
42. Zhang J, Su L, Wang Y, Deng S. Improved high-throughput sequencing of the human oral microbiome: from illumina to PacBio. Can J Infect Dis Med Microbiol 2020; 2020: 6678872.
43. Li Y, Cui J, Liu Y, Chen K, Huang L, Liu Y. Oral, tongue-coating microbiota, and metabolic disorders: a novel area of interactive research. Front Cardiovasc Med 2021; 8: 730203.
44. Vieira AT, Castelo PM, Ribeiro DA, Ferreira CM. Influence of oral and gut microbiota in the health of menopausal women. Front Microbiol 2017; 8: 1884.
45. Segata N, Haake SK, Mannon P, et al. Composition of the adult digestive tract bacterial microbiome based on seven mouth surfaces, tonsils, throat and stool samples. Genome Biol 2012; 13: R42.
46. Pandey H, Tang DWT, Wong SH, Lal D. Gut microbiota in colorectal cancer: biological role and therapeutic opportunities. Cancers 2023; 15: 866.
47. Cama?es-Gonzalvo S, Montiel-Company JM, Lobo-de-Mena M, et al. Relationship between oral microbiota and colorectal cancer: a systematic review. J Periodontal Res 2024; 59: 1071-82.
48. Koliarakis I, Messaritakis I, Nikolouzakis TK, Hamilos G, Souglakos J, Tsiaoussis J. Oral bacteria and intestinal dysbiosis in colorectal cancer. Int J Mol Sci 2019; 20: 4146.
49. Parhi L, Alon-Maimon T, Sol A, et al. Breast cancer colonization by Fusobacterium nucleatum accelerates tumor growth and metastatic progression. Nat Commun 2020; 11: 3259.
50. Abed J, Emg?rd JE, Zamir G, et al. Fap2 mediates Fusobacterium nucleatum colorectal adenocarcinoma enrichment by binding to tumor-expressed Gal-GalNAc. Cell Host Microbe 2016; 20: 215-25.
51. Abe K, Fujita M, Hayashi M, Okai K, Takahashi A, Ohira H. Gut and oral microbiota in autoimmune liver disease. Fukushima J Med Sci 2020; 65: 71-5.
52. Kunath BJ, De Rudder C, Laczny CC, Letellier E, Wilmes P. The oral-gut microbiome axis in health and disease. Nat Rev Microbiol 2024; 22: 791-805.
53. Agus A, Clément K, Sokol H. Gut microbiota-derived metabolites as central regulators in metabolic disorders. Gut 2021; 70: 1174-82.
Options
Outlines

/

〈 〉