Mung bean (Vigna radiata L.) ethanol extracts alleviate alcoholic liver injury with modulation of gut microbiota and spermidine elevation

The pathophysiology of alcoholic-associated liver disease (ALD) is multifaceted. Utilizing the gut-liver axis framework and integrated multi-omics approaches, this study systematically evaluated the therapeutic potential of mung bean (Vigna radiata L.) ethanol extracts (MBE) in ALD, and its regulatory effects on gut microbiota and serum metabolites. Chemical analysis identified vitexin, isovitexin, catechin, trigonelline, and caffeic acid as MBE’s primary bioactive compounds. In a modified NIAAA model, MBE alleviated liver injury, lipid dysregulation, inflammation, oxidative stress, and gut barrier damage via PPARα-mediated lipid metabolism and Nrf2-driven antioxidant activation. 16S rRNA sequencing and in vitro fermentation experiment revealed that MBE specifically enriched Lactobacillus johnsonii in vivo and promoted its growth in vitro, with this bacterium being closely associated with increased spermidine levels. Lactobacillus johnsonii supplementation replicated MBE’s hepatoprotection by increasing spermidine and mitigating alcohol-induced hepatic/intestinal damage. Subsequent in vivo and in vitro spermidine interventions further validated its hepatoprotection. These findings propose a novel “MBE-Lactobacillus johnsonii-spermidine-liver” regulatory mode, positioning MBE as a dietary or therapeutic candidate for ALD and offering gut-liver axis targets.