Lactiplantibacillus plantarum P101 Mitigates Alcoholic Hepatic Steatosis via AMPK Activation: Mechanistic Insights From Gut Microbiota and Metabolomics Analyses

Study Background and Research Question

Alcoholic liver disease (ALD) is a progressive disorder initiated by chronic and excessive alcohol consumption, leading to hepatic steatosis (fatty liver), fibrosis, cirrhosis, and potentially liver failure. Globally, ALD contributes to approximately 3 million deaths annually, with hepatic triglyceride accumulation (alcoholic fatty liver disease, AFLD) being the earliest and most reversible stage. The pathogenesis of AFLD involves disrupted lipid metabolism, partly driven by impaired AMP-activated protein kinase (AMPK) signaling, which balances hepatic lipid oxidation and synthesis. Given the limitations and side effects of pharmacological therapies, there is growing interest in nutritional and probiotic interventions for AFLD prevention and management. The current study by Feng et al., published in 2025, investigates whether the probiotic Lactiplantibacillus plantarum P101 (LP.P101) can ameliorate alcohol-induced hepatic lipid accumulation and explores the mechanistic role of AMPK signaling and gut microbiota in this process (reference study).

Key Innovation from the Reference Study

The central innovation of this work lies in its integrated approach combining probiotic intervention, targeted AMPK inhibition, gut microbiota profiling, and metabolomics to clarify the mechanistic link between LP.P101 administration and hepatic lipid metabolism. Specifically, the study employs the selective AMPK inhibitor dorsomorphin to dissect the causative role of AMPK activation in mediating the protective effects of LP.P101 against alcohol-induced steatosis. This allows for direct attribution of observed hepatic and metabolic changes to the restoration of AMPK signaling, rather than confounding probiotic effects alone. The research further characterizes how LP.P101 modulates gut microbial communities and identifies serum metabolites associated with AMPK activation and lipid accumulation, offering a multidimensional understanding of gut-liver axis dynamics in ALD.

Methods and Experimental Design Insights

The experimental model utilized C57BL/6 mice subjected to a 10-day ethanol feeding protocol followed by acute binge ethanol administration to induce hepatic steatosis, closely mimicking early-stage human AFLD. Mice received daily oral gavage of LP.P101 (10⁸ CFU/mL). To assess the necessity of AMPK signaling, a subset of animals was co-treated with dorsomorphin, a well-characterized AMPK inhibitor. Comprehensive phenotypic assessments included:

• Histological quantification of hepatic lipid droplets (steatosis severity)
• Serum biochemical assays (ALT, triglycerides, etc.)
• qPCR and immunoblotting for hepatic AMPK expression and phosphorylation status, along with downstream metabolic genes
• 16S rRNA sequencing of fecal samples for gut microbiota profiling
• Untargeted serum metabolomics to identify metabolites correlated with AMPK activity and lipid accumulation

The inclusion of an AMPK inhibitor arm (dorsomorphin) is critical for establishing causality between probiotic-induced AMPK activation and improvements in hepatic lipid metabolism.

Protocol Parameters

• Alcohol induction: 10 days of Lieber-DeCarli ethanol diet, followed by acute binge ethanol (5 g/kg) to model AFLD.
• Probiotic intervention: LP.P101 administered via gavage at 10⁸ CFU/mL daily throughout ethanol exposure.
• AMPK inhibition: Dorsomorphin given intraperitoneally; dosing and timing aligned to coincide with probiotic and ethanol treatments for effective pathway suppression.
• Endpoint analyses: Liver and serum harvested post-treatment for histology, biochemical markers, gene/protein expression, microbiota, and metabolomic studies.

Core Findings and Why They Matter

The results demonstrate that LP.P101 supplementation significantly reduces hepatic lipid droplet accumulation and normalizes serum ALT and triglyceride levels in alcohol-fed mice, indicating marked protection against ethanol-induced steatosis (reference study). Mechanistically, LP.P101 restores hepatic AMPK phosphorylation and upregulates related catabolic gene expression while suppressing anabolic lipogenic genes. Notably, when AMPK signaling is inhibited using dorsomorphin, these protective effects are abrogated, and biochemical and molecular markers revert to levels observed in the alcohol-only group. This establishes a direct requirement for AMPK activation in mediating the anti-steatotic actions of LP.P101. Gut microbiota analysis reveals that LP.P101 shifts the microbial balance by decreasing Firmicutes and increasing Bacteroidetes relative abundance, with specific taxa such as Parabacteroides merdae negatively correlated with lipid accumulation. Metabolomic profiling identifies stercobilinogen as a potential biomarker, showing positive correlation with AMPK activation and negative association with hepatic lipid content. These findings suggest that both microbial and metabolite changes contribute to the observed restoration of hepatic metabolic homeostasis. The study thus provides strong evidence that targeted probiotic intervention can mitigate alcohol-induced hepatic lipid accumulation via a gut microbiota–AMPK–metabolite axis. This highlights AMPK as a central node for nutritional modulation in ALD and supports further exploration of probiotics as adjunctive therapy.

Limitations and Transferability

While the study employs a robust mouse model and mechanistic inhibitor, several limitations should be noted. The short-term ethanol feeding protocol, although widely accepted, does not fully recapitulate chronic human ALD progression or its comorbidities. The specificity of dorsomorphin as an AMPK inhibitor is well-documented, but potential off-target effects, particularly in pathways such as BMP signaling, should be acknowledged. Additionally, the implications for human translation remain preliminary, as factors such as host genetics, diet, and environmental exposures may influence probiotic efficacy and gut-liver axis dynamics. Transferability to other models of hepatic steatosis (e.g., nonalcoholic fatty liver disease) or to clinical settings will require further validation. The study does not address long-term outcomes, potential immune modulation, or the stability of gut microbiota changes post-intervention. Nonetheless, the approach provides a valuable framework for dissecting the molecular underpinnings of probiotic action in metabolic liver diseases.

Comparison with Existing Internal Articles

At present, there are no internal articles directly addressing LP.P101, AMPK modulation, or the use of AMPK inhibitors in alcoholic liver disease models within this knowledge base. This highlights the novelty of the present work and underscores the need for further synthesis of AMPK-targeted interventions, both nutritional and pharmacological, in hepatic metabolic research. Future internal resources could benefit from integrating these mechanistic insights into broader discussions of gut-liver interactions and metabolic syndrome interventions.

Research Support Resources

Researchers interested in modeling AMPK pathway inhibition in hepatic or metabolic studies may consider Dorsomorphin 2HCl (SKU B1372), a selective AMPK and BMP signaling pathway inhibitor. According to the product information, Dorsomorphin 2HCl is suitable for in vitro and in vivo applications requiring targeted suppression of AMPK activation or investigation of bone morphogenetic protein signaling. Its use, as demonstrated in the reference study, allows for precise dissection of AMPK-dependent mechanisms in models of hepatic lipid metabolism and can facilitate exploration of related pathways such as osteogenic differentiation and iron homeostasis. For best results, researchers should follow recommended solubility and storage protocols as detailed by APExBIO.