Tongue color tones in Traditional Chinese Medicine correlate with liver histology of metabolic dysfunction-associated steatohepatitis in morbidly obese patients undergoing metabolic and bariatric surgery.

Objective: To determine the association of tongue color tones in morbidly obese patients with various liver histological characteristics of metabolic dysfunction-associated steatohepatitis (MASH), which is the advanced subtype of metabolic dysfunction-associated steatotic liver disease (MASLD).

Methods: A total of 60 morbidly obese adults who underwent metabolic and bariatric surgery were recruited. Liver biopsies were available for all participants and were subjected to histological assessment. The association of tongue color tones with histological parameters in the liver was investigated.

Results: MASH-related histological characteristics in the liver were closely associated with color features in distinct zones of the tongue. The values for color channels red (R), green (G), and blue (B) were increased in subjects with histological features of steatosis. Likewise, the histological characteristic of lobular inflammation was associated with distinct panels of RGB values for tongue edge zones and tongue coating. RGB values in the tongue exhibited a step-wise increase in line with grading score of liver histology. In contrast, tooth-sign on the tongue was dissociated with histological features of MASH.

Conclusion: Our clinicopathological study demonstrated a close association of color tones in the tongue with MASH-related histological characteristics in the liver of morbidly obese patients, supporting the application of tongue inspection in Traditional Chinese Medicine as a promising approach to non-invasive diagnosis of MASLD/MASH.