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

<b>Background/Objective:</b> This study investigated the relationship between the composition of oral microbiota and metabolic dysfunction-associated steatotic liver disease (MASLD) in the general population. <b>Methods:</b> 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 <i>Neisseria</i>, <i>Streptococcus</i>, <i>Fusobacterium</i>, and <i>Veillonella</i> groups. The <i>Neisseria</i> 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. <b>Results:</b> In a multivariate analysis, the <i>Veillonella</i> group was a risk factor for MASLD independent of cardiometabolic criteria compared with the <i>Neisseria</i> group. The correlation between oral bacterial species and MASLD-related items showed that <i>Neisseria</i> was negatively correlated with controlled attenuation parameters, body mass index, waist circumference, hemoglobin A1c, alanine aminotransferase, and fatty liver index. <i>Veillonella</i> 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 <i>Streptococcus</i> and <i>Fusobacterium</i> groups were not clearly associated with MASLD. <b>Conclusions:</b> Maintaining oral hygiene and preventing periodontitis may contribute to preventing MASLD and extending a healthy lifespan.