Inhibition of ADORA1 attenuates hepatic steatosis by gut microbiota-derived acetic acid from Astragalus polysaccharides

Gut dysbiosis contributes to nonalcoholic fatty liver disease (NAFLD) formation. However, the underlying molecular mechanism is not fully understood. Here, we report a novel therapeutic target for NAFLD, the hepatic adenosine receptor A1 (ADORA1) that is inhibited by gut microbiota-derived acetic acid from Astragalus polysaccharides (APS). APS supplement attenuated hepatic steatosis by reversing gut dysbiosis in high-fat diet fed mice, and reduced hepatic ADORA1 expression. Patients with hepatic steatosis showed increased expression of hepatic ADORA1, and specific ADORA1 antagonist ameliorated hepatic steatosis as well. Meanwhile, the metabolic benefits of APS were microbiota-dependent due to the production of acetic acid, which improved hepatic steatosis by suppressing ADORA1 both in vitro and in vivo resulting to the inhibition of rate-limiting enzyme for fatty acid de novo synthesis, fatty acid synthase. Our results highlight the critical role of gut microbiota-acetic acid-hepatic ADORA1 axis in NAFLD development and reveal the novel mechanism underlying the metabolic benefits of APS.