Analysis of the association between tongue coating microbiota and clinical symptoms

Objective: This study explores the correlations among tongue appearance, tongue coating microbiota, and clinical symptoms across different stages of chronic gastritis. Methods: We collected 133 samples from patients categorized into inflammation (53), atrophy (31), and intestinal metaplasia (49) groups. Clinical data were analyzed using baseline, Mental, and MaAsLin statistical methods to investigate the relationships between tongue characteristics, microbiota, and symptoms. Results: (1) Tongue and Symptom Correlation: Progression in gastritis was associated with a decrease in pale red tongues and an increase in dark-colored, red, dark red, purple, large, and greasy tongues. Although dominant bacterial genera were consistent across groups, unique genera varied significantly, with the most diversity in the intestinal metaplasia group. (2) Microbiota Variability: Statistical analysis showed no significant variations in Hp infection rates among the groups. However, specific microbiota were correlated with particular symptoms; for instance, greasy and slippery coatings were linked with positive correlations to Cyanobacteria and Chloroflexi. (3) Symptom Correlations: Stomach pain and bloating were positively correlated with Firmicutes and negatively with Bacteroidetes. Oral symptoms like bitterness were more common in the atrophy and metaplasia groups, significantly differing from the inflammation group. Conclusion: Changes in tongue appearance and microbiota across different gastritis stages mirror clinical symptoms, suggesting a diagnostic link. These findings could aid in developing precise diagnostic tools and early warning systems for chronic gastritis based on microbiome data.