Changes in the Intestinal Microbiome and Alcoholic and Nonalcoholic Liver Diseases: Causes or Effects?

Abstract

The prevalence of fatty liver diseases is increasing rapidly worldwide; after treatment of hepatitis C virus infection becomes more widespread, fatty liver diseases are likely to become most prevalent liver disorders. Although fatty liver diseases are associated with alcohol, obesity, and the metabolic syndrome, their mechanisms of pathogenesis are not clear. Development and progression of fatty liver, alcoholic, and non-alcoholic liver disease (ALD) all appear to be influenced by the composition of the microbiota. The intestinal microbiota have been shown to affect pre-cirrhotic and cirrhotic stages of liver diseases, which could lead to new strategies for their diagnosis, treatment, and study. We review differences and similarities in the cirrhotic and pre-cirrhotic stages of non-alcoholic fatty liver disease (NAFLD) and ALD. Differences have been observed in these stages of alcohol-associated disease in patients who continue to drink compared with those who stop, with respect to the composition and function of the intestinal microbiota and intestinal integrity. NAFLD and the intestinal microbiota also differ between patients with and without diabetes. We also discuss the potential of microbial therapy for patients with NAFLD and ALD.

Gut Microbiome-Based Metagenomic Signature for Non-invasive Detection of Advanced Fibrosis in Human Nonalcoholic Fatty Liver Disease

“…(Chen et al, 2016) Therefore, changes in gut microbiome have been linked to NAFLD, and NASH. (Betrapally et al, 2016; Henao-Mejia et al, 2012)…”

Link between gut‐microbiome derived metabolite and shared gene‐effects with hepatic steatosis and fibrosis in NAFLD

“…Compositional changes in gut microbiota have been proposed to mechanistically contribute to the progression of NAFLD . A higher proportion of Gram‐negative bacterial species in the gut microbiome has been reported in NAFLD and significant changes in the gut microbiome have been linked to NAFLD, NASH and NASH‐related liver fibrosis . We report significant correlation between the abundance of several bacterial species in the gut microbiome and the circulating level of 3‐(4‐hydroxyphenyl)lactacte, including bacterial species associated with advanced fibrosis in a previous study .…”

Pathogenesis of Nonalcoholic Steatohepatitis: Interactions between Liver Parenchymal and Nonparenchymal Cells

“…The most recent study found the global prevalence of NAFLD was 25% [3]. Individuals with components of metabolic syndrome (MS), such as obesity, insulin resistance, and hyperlipidemia, have an increased risk of developing NAFLD, as positive correlations have been noticed between NAFLD and components of MS [2, 4–6]. NAFLD is closely related to obesity; however, 5–8% of nonobese (lean) subjects also develop NAFLD [7].…”