Ginseng Compound Rh4 Fights Colorectal Cancer by Reshaping Gut Bacteria and Bile Acids

Colorectal cancer ranks as the second leading cause of cancer death worldwide, and emerging evidence links gut microbiota dysbiosis to its development. This study from Northwest University investigated whether ginsenoside Rh4 (Rh4), a rare bioactive compound from Panax ginseng (purity ≥98%), could suppress CRC by modulating gut bacteria and their metabolic outputs. Using the well-validated AOM/DSS mouse model of colitis-associated colorectal cancer, researchers administered 60 mg/kg Rh4 daily by oral gavage and tracked tumor formation, intestinal barrier integrity, immune markers, and microbiome composition over a multi-cycle treatment period.

Rh4 treatment significantly improved survival rates, reduced body weight loss, and shortened colon lengths compared to untreated AOM/DSS controls. Tumor number and volume were markedly reduced in the Rh4 group (p<0.01 and p<0.001 respectively). Histopathological scoring via H&E staining confirmed reduced mucosal damage and dysplasia. Goblet cell counts increased with Rh4 treatment, indicating restored mucosal barrier function, and FD4 intestinal permeability assays showed significantly reduced gut leakiness. Protein expression of tight junction markers Claudin-1 and E-cadherin was elevated, supporting structural barrier repair.

To confirm gut microbiota dependence, the team treated mice with a broad-spectrum antibiotic cocktail (ampicillin, neomycin, metronidazole, vancomycin) to deplete the microbiome. In germ-free conditions, Rh4 lost its anti-tumor efficacy, demonstrating that intact gut bacteria are required. Fecal microbiota transplantation (FMT) from Rh4-treated donor mice into antibiotic-depleted recipients successfully transferred the anti-tumor phenotype, providing strong causal evidence. 16S rRNA sequencing of fecal samples showed that Rh4 significantly increased alpha diversity and specifically enriched Akkermansia muciniphila while reducing pathogenic genera including Fusobacterium and Escherichia-Shigella.

Metabolomic profiling using UPLC-Q Exactive HF mass spectrometry identified bile acid metabolism as the most significantly altered pathway. Specifically, Rh4 elevated fecal UDCA levels. Oral colonization with A. muciniphila (1×10⁹ CFU/day for three weeks) recapitulated this bile acid shift, and mechanistic assays confirmed that A. muciniphila enhanced activity of 7α-hydroxysteroid dehydrogenase (7α-HSDH), the key enzyme converting primary to secondary bile acids including UDCA. Transcriptomic analysis via RNA sequencing identified the FXR-TLR4-NF-κB axis as the downstream signaling cascade. UDCA activated farnesoid X receptor (FXR), which in turn suppressed TLR4 and downstream NF-κB phosphorylation (p-p65), reducing pro-inflammatory cytokine expression and tumor proliferation marker Ki-67.

Finally, direct UDCA supplementation (100 mg/kg daily gavage) in a CT26 syngeneic tumor-bearing mouse model reproduced the anti-tumor effects, with reduced tumor growth and downregulated NF-κB signaling, confirming UDCA as the functional mediator. Taken together, these findings construct a complete mechanistic chain: Rh4 → A. muciniphila enrichment → 7α-HSDH activation → UDCA production → FXR activation → TLR4/NF-κB suppression → reduced CRC. The study positions Rh4 as a promising microbiome-targeted natural compound for CRC prevention and as a rationale for UDCA-based therapeutic strategies.