Disruption of Enterohepatic Circulation of Bile Acids Ameliorates Small Bowel Resection Associated Hepatic Injury

Background: Massive small bowel resection (SBR) is associated with liver injury and fibrosis. Efforts to elucidate the driving force behind hepatic injury have identified multiple factors, including the generation of toxic bile acid metabolites.

Methods: Sham, 50% proximal, and 50% distal SBR were carried out in C57BL/6 mice to determine the effect of jejunal (proximal SBR) versus ileocecal resection (distal SBR) on bile acid metabolism and liver injury. Tissues were harvested at 2 and 10-week postoperative timepoints.

Results: When compared with 50% proximal SBR, mice that underwent distal SBR exhibited less hepatic oxidative stress as verified by decreased mRNA expression of tumor necrosis factor-α (TNFα, p ≤ 0.0001), nicotinamide adenine dinucleotide phosphate oxidase (NOX, p ≤ 0.0001), and glutathione synthetase (GSS, p ≤ 0.05). Distal SBR mice also exhibited a more hydrophilic bile acid profile with reduced abundance of insoluble bile acids (cholic acid (CA), taurodeoxycholic acid (TCA), and taurolithocholic acid (TLCA)), and increased abundance of soluble bile acids (tauroursodeoxycholic acid (TUDCA)). In contrast with proximal SBR, ileocecal resection alters enterohepatic circulation leading to reduced oxidative stress and promotes physiological bile acid metabolism.

Conclusion: These findings challenge the notion that preservation of the ileocecal region is beneficial in patients with short bowel syndrome. Administration of selected bile acids may present potential therapy to mitigate resection-associated liver injury.

Level of evidence: III-Case-Control Study.