Bacterial translocation in experimental stroke: what happens to the gut barrier?

Area of Science:

• Neuroscience
• Gastroenterology
• Infectious Diseases

Background:

• Post-stroke infections are a significant complication, but their origins remain unclear.
• Bacterial translocation (BT), the movement of microbes across the intestinal barrier, is implicated in critical illnesses but not previously studied in stroke models.
• Understanding the link between stroke and gut barrier integrity is crucial for managing post-stroke complications.

Purpose of the Study:

• To investigate bacterial translocation as a source of infection following a stroke in an animal model.
• To determine if stroke induces intestinal damage that facilitates bacterial translocation.
• To correlate the extent of bacterial translocation with histopathological changes in the ileum.

Main Methods:

• A permanent middle cerebral artery occlusion (MCAO) model was established in rats.
• Bacterial translocation was assessed by comparing microbial flora in tissues (blood, lymph nodes, liver, spleen, lungs) with intestinal microflora using phenotypic methods and antibiotyping.
• Ileum tissue integrity was evaluated through histopathological examination and morphometric analysis at 24, 48, and 72 hours post-stroke.

Main Results:

• Bacterial proliferation was detected in 55.5%, 45.4%, and 30% of MCAO rats at 24, 48, and 72 hours, respectively.
• Sham groups showed no bacterial proliferation.
• Significantly higher bacterial proliferation and ileum tissue injury scores were observed in MCAO groups compared to sham groups over time (p < 0.05).

Conclusions:

• Stroke induces mucosal damage in the ileum.
• This damage facilitates bacterial translocation from the gut into systemic tissues.
• Bacterial translocation is a key mechanism contributing to post-stroke infections.