Background/Objectives: The aim of this study is to evaluate the relationship between adherence to the Mediterranean diet and intestinal microbiota metabolite trimethylamine N-oxide (TMAO) levels, systemic inflammation markers, and oxidative stress parameters in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Methods: MASLD patients whose fatty liver and fibrosis severity were determined with FibroScan and a healthy control group were included in the study. In addition to the routine biochemical parameters, serum TMAO levels, inflammatory cytokines (IL-6, IL-10, TNF-α), and oxidative stress indicators (malondialdehyde, glutathione, and MDA/GSH ratio) of all participants were measured. In comparing these parameters between fibrosis groups, adjustment for potential confounding variables (age, BMI, sex, comorbidity, relevant medication use, MEDAS score, and physical activity) was performed. Following anthropometric evaluations, the adherence levels of the participants to the Mediterranean diet were determined by the Mediterranean Diet Adherence Screening Scale (MEDAS), and their physical activity levels were determined through the International Physical Activity Questionnaire-Short Form (IPAQ-SF). Results: Individuals diagnosed with MASLD had significantly lower adherence to the Mediterranean diet and lower physical activity levels compared with healthy controls. Among the inflammatory parameters, IL-6 levels were significantly higher in the advanced fibrosis group than in the early-stage and significant fibrosis groups, while TNF-α levels were significantly higher in the advanced fibrosis group than in the early fibrosis group. No significant differences were observed among the groups in TMAO, IL-10, GSH levels, or the MDA/GSH ratio; however, among the oxidative stress markers, MDA levels were significantly higher in the early fibrosis group than in the significant fibrosis group. Conclusions: In MASLD patients, fibrosis severity was associated with alterations in TMAO, inflammatory, and oxidative stress markers, with increased TNF-α and IL-6 levels reflecting a high inflammatory burden as fibrosis progressed. Lower TMAO levels in fibrosis groups likely reflect reduced hepatic FMO3 activity, lower fish intake, and medication use, while elevated MDA levels in early-stage fibrosis suggest that lipid peroxidation may be more prominent in the initial phases of disease. Mediterranean diet adherence and physical activity were inversely associated with pro-inflammatory markers and MASLD severity, being highest in the control group, suggesting a potential protective role for these lifestyle factors in MASLD progression.
Kazdal et al. (Thu,) studied this question.