Obstructive jaundice promotes bacterial translocation from the gut

Area of Science:

• Gastroenterology
• Microbiology
• Surgical Pathology

Background:

• Obstructive jaundice, characterized by elevated bilirubin levels, can potentially disrupt the gastrointestinal barrier.
• The role of bile in maintaining intestinal homeostasis and preventing bacterial translocation is not fully understood.

Purpose of the Study:

• To investigate whether obstructive jaundice promotes bacterial translocation from the gastrointestinal tract to visceral organs in a mouse model.
• To identify the underlying mechanisms, including bacterial overgrowth and mucosal changes, contributing to bacterial translocation.

Main Methods:

• A mouse model of obstructive jaundice was established by ligating the common bile duct.
• Control and sham-ligated groups were used for comparison.
• Bilirubin levels, bacterial translocation incidence, cecal bacterial populations, and intestinal histology were assessed seven days post-surgery.

Main Results:

• Bile duct-ligated mice exhibited significantly elevated bilirubin levels and a higher incidence of bacterial translocation compared to control and sham-ligated groups.
• Gram-negative enteric bacilli showed a 100-fold increase in cecal populations in ligated mice with bacterial translocation.
• Intestinal histology revealed subepithelial edema in the ileal villi of ligated mice, while control and sham groups showed normal mucosal appearance.

Conclusions:

• Obstructive jaundice promotes bacterial translocation, primarily driven by intestinal overgrowth of enteric bacilli.
• The absence of bile in the gastrointestinal tract is a key factor enabling this overgrowth.
• A combination of bacterial overgrowth and mucosal injury, specifically subepithelial edema, appears to be responsible for promoting bacterial translocation in obstructive jaundice.