Serum Zonulin as a Potential Biomarker in Nonalcoholic Fatty Liver Disease (NAFLD): A Case-Control Study

Abstract

Background: The buildup of excess fat in the liver is a defining characteristic of non-alcoholic fatty liver disease (NAFLD), the most common chronic liver condition globally. NAFLD is also closely linked to metabolic syndrome. New research points to increased intestinal permeability as a possible mechanism by which NAFLD-related liver inflammation and injury persist, with increased serum zonulin levels serving as the primary driver.

Objective: This study aimed to investigate serum zonulin levels and liver enzyme activities (ALT, AST, and GGT) in NAFLD patients and assess the diagnostic potential of zonulin as a biomarker for the disease.

Methods: Ninety people, 60 with NAFLD and 30 healthy controls, ranging in age from 30 to 60 years old, were involved in the clinical case-control study. In order to assess the amounts of serum zonulin and liver enzymes, blood samples were taken following an overnight fast. In order to find noteworthy distinctions and correlations, statistical tests were run.
Results: Serum zonulin concentrations were markedly elevated in NAFLD patients relative to healthy controls (patients: 72.50 ± 8.24 ng/ml vs. controls: 57.17 ± 8.26 ng/ml, p < 0.01). Levels of liver enzymes (ALT, AST, and GGT) were also markedly elevated in NAFLD patients (all p < 0.01). A strong positive correlation was found between serum zonulin levels and liver enzyme concentrations (GGT, ALT, AST), suggesting that increased intestinal permeability contributes to the development of NAFLD. Receiver Operating Characteristic (ROC) analysis demonstrated excellent diagnostic accuracy for zonulin, with an AUC of 0.903, supporting its potential as a biomarker for NAFLD.

Conclusion:
Increased intestinal permeability and liver dysfunction are directly associated with higher blood zonulin concentrations in NAFLD patients. A potential diagnostic technique for better clinical management of NAFLD and earlier disease identification could be measuring zonulin levels.