Intestinal dysbiosis in nonalcoholic fatty liver disease (NAFLD): focusing on the gut–liver axis

Abstract

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders in humans, partly because it is closely related to metabolic disorders of the liver with increasing prevalence. NAFLD begins with hepatic lipid accumulation, which may cause inflammation and eventually lead to fibrosis in the liver. Numerous studies have demonstrated the close relationship between gut dysfunction (especially the gut microbiota and its metabolites) and the occurrence and progression of NAFLD. The bidirectional communication between the gut and liver, named the gut–liver axis, is mainly mediated by the metabolites derived from both the liver and gut through the biliary tract, portal vein, and systemic circulation. Herein, we review the effects of the gut–liver axis on the pathogenesis of NAFLD. We also comprehensively describe the potential molecular mechanisms from the perspective of the role of liver-derived metabolites and gut-related components in hepatic metabolism and inflammation and gut health, respectively. The study provides insights into the mechanisms underlying current summarizations that support the intricate interactions between a disordered gut and NAFLD and can provide novel strategies to lessen the prevalence and consequence of NAFLD.

Keywords:

• Gut–liver axis
• inflammation
• intestinal health
• lipid metabolism
• metabolites
• nonalcoholic fatty liver disease (NAFLD)

Disclosure statement

The authors declare that they have no conflict of interests.

Data availability statement

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

Additional information

Funding

The authors acknowledge the financial support from the State Key Laboratory of Animal Nutrition (2004DA125184G2102), the Agricultural Science and Technology Innovation Program (CAAS-ZDRW202006-02, ASTIP-IAS07), and Central Public-interest Scientific Institution Basal Research Fund (Y2021GH01-4) in China.