An exploratory analysis on the association between suicidal ideation and the microbiome in patients with or without major depressive disorder

Abstract Background Scarce research has investigated associations between suicidal ideation and the gut microbiota. We aimed to explore variations in the gut microbiome associated with suicidal ideation and major depressive disorder (MDD). Results Among the 140 participants, significant differences in Beta diversity were found between MDD patients with (n=43) or without suicidal ideation (n=34), and healthy volunteers (n=42) (all p<0.001). The strain of g-Phascolarctobacteriumwas found to have significant positive associations with scores of BSSI and BSSI Part 1 (suicidal ideation), particularly in MDD patients with suicidal ideation, after controlling for demographic and mood covariates. Conclusion We found different compositions and diversities of the gut microbiome associated with suicidal ideations. Potential mechanisms need further investigation to establish whether this reflects a biological process that might be the focus for intervention development.