Effect of Oral and Gut Microbiota, Dietary Intake, and Genetic Polymorphisms on Older Adults with Metabolic Dysfunction Associated Fatty Liver Disease

Objective: This study aimed to investigate the factors involved in the development and progression of metabolic dysfunction-associated fatty liver disease (MASLD) in older adults from various aspects. Methods: Among general residents aged ≥60 years who participated in a health checkup project, 124 individuals in a normal group and 77 in an MASLD group were targeted in this study. Differences in nutrient intake, MASLD-related single nucleotide polymorphisms (SNPs), and oral and gut microbiota between the normal and MASLD groups were investigated. Furthermore, multivariate analysis was conducted to determine which cardiometabolic criteria were associated with the identified variables. Result: The MASLD group had increased oral Veillonella and Megasphaera and decreased gut Blautia . Oral Veillonella and Magasphaera were positively associated with body mass index (BMI), waist circumference, and systolic blood pressure. Gut Blautia negatively correlated with BMI, waist circumference, fasting blood sugar, HbA1c, triglycerides, and positively correlated with high-density lipoprotein cholesterol. However, no association was observed between nutritional intake and SNPs. Conclusion: Because oral and gut microbiota are strongly involved in MASLD in older individuals, improving oral hygiene and probiotics may prevent the onset and progression of MASLD by improving the oral and gut environment.