Non-alcoholic fatty liver disease (
NAFLD) is the hepatic consequence of
metabolic syndrome, which often also includes
obesity, diabetes, and
dyslipidemia. The connection between gut microbiota (GM) and
NAFLD has attracted significant attention in recent years. Data has shown that GM affects hepatic lipid metabolism and influences the balance between pro/anti-inflammatory effectors in the liver. Although studies reveal the association between GM
dysbiosis and
NAFLD, decoding the mechanisms of gut
dysbiosis resulting in
NAFLD remains challenging. The potential pathophysiology that links GM
dysbiosis to
NAFLD can be summarized as: (1) disrupting the balance between energy harvest and expenditure, (2) promoting hepatic
inflammation (impairing intestinal integrity, facilitating
endotoxemia, and initiating inflammatory cascades with
cytokines releasing), and (3) altered biochemistry metabolism and GM-related metabolites (i.e.,
bile acid,
short-chain fatty acids,
aromatic amino acid derivatives,
branched-chain amino acids,
choline,
ethanol). Due to the hypothesis that probiotics/synbiotics could normalize GM and reverse
dysbiosis, there have been efforts to investigate the
therapeutic effect of probiotics/synbiotics in patients with
NAFLD. Recent randomized clinical trials suggest that probiotics/synbiotics could improve
transaminases, hepatic steatosis, and reduce hepatic
inflammation. Despite these promising results, future studies are necessary to understand the full role GM plays in
NAFLD development and progression. Additionally, further data is needed to unravel probiotics/synbiotics efficacy, safety, and sustainability as a novel pharmacologic approaches to
NAFLD.