OCLN and Hepatic steatosis: Oral administration of A. muciniphila can normalize the mucus thickness of the inner layer, increase the number of goblet cells, and upregulate the expression of tight-junction proteins, including occludin, claudins, and ZO-1, ZO-2, and ZO-3 in the gut of both HFD-feeding obese mice and mice with alcoholic fatty liver [69,70].