Leaky gut biomarkers in depression and suicidal behavior

Area of Science:

• Neuroscience
• Gastroenterology
• Psychiatry

Background:

• Inflammation is linked to major depressive disorder (MDD) and suicidal behavior.
• The 'leaky gut hypothesis' proposes increased intestinal permeability contributes to this link via bacterial translocation.
• Understanding this connection may offer new therapeutic targets.

Purpose of the Study:

• To investigate plasma levels of gut permeability markers in patients with recent suicide attempts (rSA), MDD without a history of suicide attempts (nsMDD), and healthy controls (HC).
• To correlate these markers with symptom severity and inflammation.

Main Methods:

• Plasma levels of zonulin, intestinal fatty acid binding protein (I-FABP), soluble CD14, and interleukin-6 (IL-6) were measured.
• Participants included rSA (n=54), nsMDD (n=13), and HC (n=17) groups.
• Symptom severity was assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS) and Suicide Assessment Scale (SUAS).

Main Results:

• The rSA group showed significantly higher I-FABP and lower zonulin levels compared to nsMDD and HC groups (P < 0.001).
• IL-6 positively correlated with I-FABP and negatively with zonulin.
• I-FABP levels correlated positively with MADRS and SUAS scores across all subjects, and notably in the nsMDD group.

Conclusions:

• Findings support the 'leaky gut hypothesis' in the context of inflammation and suicidal behavior.
• These preliminary results warrant further investigation in larger cohorts to confirm the association.