Effect of Oral Microbiota Composition on Metabolic Dysfunction-Associated Steatotic Liver Disease in the General Population.

Background/Objective: This study investigated the relationship between the composition of oral microbiota and metabolic dysfunction-associated steatotic liver disease (MASLD) in the general population. Methods: In total, 712 participants in a health check-up project were divided into four oral microbiota patterns by principal component analysis and cluster analysis; they were included in Neisseria, Streptococcus, Fusobacterium, and Veillonella groups. The Neisseria group had the largest number of patients and was used as a reference group to compare the incidence of MASLD and cardiometabolic criteria with the other groups. Results: In a multivariate analysis, the Veillonella group was a risk factor for MASLD independent of cardiometabolic criteria compared with the Neisseria group. The correlation between oral bacterial species and MASLD-related items showed that Neisseria was negatively correlated with controlled attenuation parameters, body mass index, waist circumference, hemoglobin A1c, alanine aminotransferase, and fatty liver index. Veillonella showed a positive correlation with controlled attenuation parameters, waist circumference, body mass index, blood pressure, triglycerides, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, and fatty liver index, and a negative correlation with high-density lipoprotein cholesterol. In contrast, the Streptococcus and Fusobacterium groups were not clearly associated with MASLD. Conclusions: Maintaining oral hygiene and preventing periodontitis may contribute to preventing MASLD and extending a healthy lifespan.