Germ-free mice colonised with the gut microbiota of offspring born to obese dams have an increased intestinal permeability (determined by increased plasma fluorescein isothiocyanate dextran levels), hepatic inflammation (increased hepatic TNF mRNA and hepatic macrophage count), and susceptibility to non-alcoholic fatty liver disease (NAFLD), determined by a histological examination of liver sections for steatosis and the infiltration of inflammatory cells [116]. The gene discussed is TNF; the disease is metabolic dysfunction-associated steatotic liver disease.