Higher Dietary Intake of Live Microbes is Associated with Reduced Risk of Liver Fibrosis Progression in MASLD: Evidence from the NHANES 2017–2020 Cross-Sectional Study in the United States

INTRODUCTION: This study aimed to investigate the potential relationship between live microbe intake and advanced liver fibrosis in patients with Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD). METHODS: Individuals with complete Vibration-Controlled Transient Elastography (VCTE) and dietary data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020 were included. Generalized Additive Models (GAMs) were constructed to evaluate the relationship between live microbe intake and severity of hepatic steatosis and fibrosis, adjusting for potential confounders. Subgroup analyses and interaction tests assessed potential modifying effects of sex, age, Body Mass Index (BMI), liver enzymes, and alcohol consumption. Sensitivity analyses were performed to confirm robustness. RESULTS: A total of 2,533 individuals with MASLD were analyzed. GAM analyses showed no significant association between dietary live microbe intake and hepatic steatosis severity measured by Controlled Attenuation Parameter (CAP) (p = 0.779). However, there was a significant inverse relationship between live microbe intake and Liver Stiffness Measurement (LSM), indicating reduced liver fibrosis severity with higher microbe intake (p = 0.004). Subgroup and interaction analyses consistently supported this association across different age groups, sexes, BMI categories, and liver enzyme levels. DISCUSSION: These findings highlight a significant association between higher dietary intake of live microbes and reduced severity of liver fibrosis, emphasizing the potential role of dietary modification in managing liver fibrosis in MASLD. CONCLUSION: Higher dietary intake of live microbes is significantly associated with reduced liver fibrosis severity in MASLD, suggesting a potential protective role of dietary microbes in liver health.