Intestinal permeability in non-alcoholic fatty liver disease: the gut-liver axis.

The gut-liver axis model has helped to explain the liver steatosis (NAFLD) and steatohepatitis (NASH) etiopathogenesis. The discovery of a key role for an altered intestinal permeability (IP) in this pathophysioligcal framework has closed the link between gut lumen antigenic/toxic substances and systemic and liver inflammation in NAFLD and obesity, metabolic syndrome. Recent evidence from the literature show how IP can be modulated by several non-pharmacological and pharmacological agents and be the target for future preventive and curative treatment of NAFLD and NASH. In this review we describe the concept of IP, its ultrastructural basis, its role in the NALFD pathophysiology and emerging evidence on non-pharmacological and pharmacological agents able to favourably modulate it.