Cholecystohepatic shunt pathway reduces secondary bile acid accumulation to enhance natural killer T cell‐mediated anti‐hepatocellular carcinoma immunity

Abstract Background and Aim The impact of cholecystectomy, which blocks the cholecystohepatic shunt pathway (CHSP), on the prognosis of patients with hepatocellular carcinoma (HCC) is unclear. Hepatic secondary bile acids (BAs) inhibit natural killer T (NKT) cell‐mediated immunity against HCC, and the regulation of homeostasis of hepatic secondary BAs is controlled by the CHSP. However, the influence of CHSP on NKT cell‐mediated immunity against HCC remains unclear. Methods The clinical data of hospitalized patients undergoing HCC resection were collected. Meanwhile, an in situ HCC mouse model was established, and the CHSP was augmented using oleanolic acid (OA). Results After 1:1 propensity score matching, Cox regression analysis revealed that cholecystectomy was an independent risk factor for HCC recurrence after hepatectomy ( P = 0.027, hazard ratio: 1.599, 95% confidence interval: 1.055–2.422). Experimentally, when OA enhanced CHSP, a significant decrease was observed in the accumulation of secondary BAs in the livers of mice. Additionally, a significant increase was observed in the levels of C‐X‐C ligand 16 and interferon γ in the serum and tumor tissues. Further, the percentage of C‐X‐C receptor 6 (+) NKT cells in the tumor tissues increased significantly, and the growth of liver tumors was inhibited. Conclusions This clinical study revealed that cholecystectomy promoted the recurrence after radical hepatectomy in patients with HCC. Preserving the normal‐functioning gallbladder as much as possible during surgery may be beneficial to the patient's prognosis. Further investigation into the mechanism revealed that CHSP enhanced NKT cell‐mediated immunity against HCC by reducing the hepatic accumulation of secondary BAs.