Anxiety and depression are common comorbidities in gastroenterology patients but are frequently undisclosed or overlooked, especially when patients report no obvious physical GI symptoms. This study addresses a gap in prior research (which examined gut barrier dysfunction and microbiota separately) by directly linking gut dysbiosis and intestinal barrier permeability to mental health status, even in physically asymptomatic individuals. This suggests the gut could be a novel therapeutic target for managing anxiety and depression.
The researchers analyzed stool microbiota and plasma samples from 50 subjects who were physically asymptomatic for GI disorders — 22 met DSM-5 criteria for depressive or anxiety disorder (DEP/ANX) and 28 were healthy controls (NODEPANX). Using LEfSe and PICRUSt analyses, they found significant gut dysbiosis and altered metagenomic gene signatures (including overrepresented LPS biosynthesis genes) in the DEP/ANX group. Plasma biomarkers of gut barrier integrity — zonulin, FABP2, and LPS — were all significantly elevated in the DEP/ANX group compared to controls, supporting the hypothesis that gut dysbiosis and increased intestinal permeability are linked to anxiety and depression, independent of GI symptoms.
Stevens BR, Goel R, Seungbum K, Richards EM, Holbert RC, Pepine CJ, Raizada MK. Increased human intestinal barrier permeability plasma biomarkers zonulin and FABP2 correlated with plasma LPS and altered gut microbiome in anxiety or depression. Gut. 2018 Aug;67(8):1555-1557. doi:10.1136/gutjnl-2017-314759.