Intestinal Permeability and Depression-A Narrative Review of Selected Blood-Based Biomarkers

Area of Science:

• Neuroscience
• Gastroenterology
• Psychiatry

Background:

• The intestinal barrier's role in depression pathophysiology is increasingly recognized.
• Blood-based markers of intestinal permeability are being investigated as potential indicators in depression.

Purpose of the Study:

• To review the current literature on blood markers of intestinal permeability in depression.
• To assess the consistency and clinical utility of these markers.

Main Methods:

• A structured literature search of PubMed and EMBASE was conducted.
• Studies focused on zonulin, intestinal fatty acid-binding protein (I-FABP), lipopolysaccharides (LPS), LPS-binding protein (LBP), and soluble CD14 (sCD14).

Main Results:

• Studies report altered intestinal permeability markers in depression, but findings are inconsistent.
• Small sample sizes and methodological variations complicate interpretation.
• Some altered biomarker levels correlated with disease severity or treatment response.

Conclusions:

• Current evidence does not support routine clinical use of these markers for depression.
• Further research is necessary to validate their role in psychiatric populations.
• Validated markers could help identify inflammation-related depression subtypes and personalize treatment.