# Inflammatory Bowel Diseases and Non-Alcoholic Fatty Liver Disease: Piecing a Complex Puzzle Together

## TL;DR

This review explores the complex relationship between inflammatory bowel diseases and non-alcoholic fatty liver disease, highlighting current understanding and gaps in knowledge.

## Contribution

The paper provides a comprehensive overview of potential mechanisms linking IBD and NAFLD, identifying areas for future research.

## Key findings

- IBD patients have a higher prevalence of NAFLD compared to the general population.
- Multiple mechanisms, including inflammation and microbiota changes, are hypothesized to link IBD and NAFLD.
- The exact pathophysiological connection between the two diseases remains poorly understood.

## Abstract

Inflammatory bowel diseases (IBD), comprising Crohn’s disease and ulcerative colitis, are systemic and multifaceted disorders which affect other organs in addition to the gastrointestinal tract in up to 50% of cases. Extraintestinal manifestations may present before or after IBD diagnosis and negatively impact the intestinal disease course and patients’ quality of life, often requiring additional diagnostic evaluations or specific treatments. Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. Current evidence shows an increased prevalence of NAFLD (and its more advanced stages, such as liver fibrosis and steatohepatitis) in IBD patients compared to the general population. Many different IBD-specific etiopathogenetic mechanisms have been hypothesized, including chronic inflammation, malabsorption, previous surgical interventions, changes in fecal microbiota, and drugs. However, the pathophysiological link between these two diseases is still poorly understood. In this review, we aim to provide a comprehensive overview of the potential mechanisms which have been investigated so far and highlight open issues still to be addressed for future studies.