Leaky gut biomarkers in depression and suicidal behavior

• Published in: Acta psychiatrica Scandinavica Vol. 139; no. 2; pp. 185 - 193
• Main Authors: Ohlsson, L., Gustafsson, A., Lavant, E., Suneson, K., Brundin, L., Westrin, Å., Ljunggren, L., Lindqvist, D.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.02.2019; John Wiley and Sons Inc
• Subjects: Adult; Bacterial Translocation - genetics; Biomarkers; Biomarkers - blood; CD14 antigen; Clinical Medicine; Cross-Sectional Studies; Depressive Disorder, Major - diagnosis; Depressive Disorder, Major - metabolism; Digestive system; Enterocytes; Enterocytes - microbiology; Fatty acid-binding protein; Fatty Acid-Binding Proteins - blood; Female; Gastrointestinal tract; Haptoglobins; Humans; Hypotheses; Inflammation; Inflammation - metabolism; Interleukin-6 - blood; Intestine; Intestine, Small - cytology; Intestine, Small - metabolism; Intestine, Small - physiopathology; Klinisk medicin; Lipopolysaccharide Receptors - blood; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Mental depression; Middle Aged; Original; Permeability; Plasma levels; Protein Precursors - blood; Psychiatry; Psykiatri; Self destructive behavior; Severity of Illness Index; Suicidal behavior; Suicidal Ideation; Suicide; Suicide, Attempted - psychology; Suicides & suicide attempts; intestinal permeability; zonulin; suicide, attempted; depressive disorder, major; intestinal fatty acid binding protein
• ISSN: 0001-690X; 1600-0447; 1600-0447
• DOI: 10.1111/acps.12978

Inflammation is associated with major depressive disorder (MDD) and suicidal behavior. According to the 'leaky gut hypothesis', increased intestinal permeability may contribute to this relationship via bacterial translocation across enterocytes. We measured plasma levels of gut permeability markers, in patients with a recent suicide attempt (rSA), MDD subjects with no history of a suicide attempt (nsMDD), and healthy controls (HC), and related these markers to symptom severity and inflammation. We enrolled rSA (n = 54), nsMDD (n = 13), and HC (n = 17). Zonulin, intestinal fatty acid binding protein (I-FABP), soluble CD14, and interleukin-6 (IL-6) were quantified in plasma. Montgomery-Åsberg Depression Rating Scale (MADRS) and Suicide Assessment Scale (SUAS) were used for symptom assessments. The rSA group displayed higher I-FABP and lower zonulin levels compared with both the nsMDD and the HC groups (all P < 0.001). IL-6 correlated positively with I-FABP (r = 0.24, P < 0.05) and negatively with zonulin (r = -0.25, P < 0.05). In all subjects, I-FABP levels correlated positively with MADRS (r = 0.25, P < 0.05) and SUAS scores (r = 0.38, P < 0.001), and the latter correlation was significant also in the nsMDD group (r = 0.60, P < 0.05). The 'leaky gut hypothesis' may improve our understanding of the link between inflammation and suicidal behavior. These findings should be considered preliminary until replicated in larger cohorts.