Probiotic Fermentation Improves Shenzhi Decoction's Hepatoprotection via Gut-Liver Axis Modulation: A Multi-Omics Study on Acute Liver Injury.

Abstract

Introduction: Traditional Chinese Medicine (TCM), with its multi-target action and holistic regulatory mechanism, offers a promising alternative to modern health management. Shenzhi Decoction (SZD) is a case in point. It originated in the long-term application of TCM in liver health. In recent years, to enhance the bioavailability and biological activity of its components, researchers have further co-fermented SZD with specific probiotics to develop Shenzhi Jiaosu (SZJS). SZJS showed a better hepatoprotective effect than SZD, but its efficacy was unknown. This study aims to compare the protective effects of SZD and SZJS in a CCl4-induced acute liver injury model and to examine their potential mechanisms of action.

Materials and methods: SZD uses a combination of probiotics for fermentation, including patented strains Lactobacillus plantarum (RZKLp100), Lactobacillus casei (ZKLc1221), and Lactobacillus acidophilus (RZKLa0701). TOF-MS was used to detect the chemical composition of SZD and SZJS. CCL4 was used to construct a mouse model for acute liver injury, and SZD or SZJS were given to treat the injury. Liver injury and oxidative stress were evaluated by measuring serum ALT/AST levels, antioxidant enzyme activities, and histopathological examination. Bulk RNA sequencing, network pharmacology, and molecular docking were employed to identify potential mechanisms and targets. HE staining and IHC were used to assess gut barrier integrity, and 16S rRNA sequencing was used to assess gut microbial diversity.

Results: Probiotic fermentation significantly altered the chemical profile of SZD, enriching bioactive metabolites such as L-methionine and biochanin A derivatives. SZJS demonstrated superior efficacy compared with SZD in alleviating liver damage, reducing ALT/AST levels, restoring antioxidant enzyme activity, and reversing pathological changes. Transcriptome analysis revealed enhanced regulation of immune and metabolic pathways, while network pharmacology and molecular docking identified EGFR, PTGS2, and TLR9 as key molecular targets. Furthermore, SZJS improved gut barrier integrity and microbiota composition, enriching beneficial genera and microbial functions involved in detoxification and redox homeostasis.

Discussion: These findings suggest that probiotic fermentation enhances the hepatoprotective activity of SZD by reshaping its chemical composition and promoting coordinated regulation of the gut-liver axis, inflammation, oxidative stress, and metabolic homeostasis.

Conclusion: Probiotic fermentation can significantly enhance the liver-protecting efficacy of SZD by reshaping the chemical substance basis. By integrating multi-omics results, the synergistic mechanism may be related to the regulation of the "gut-liver axis".