Comparative Metaproteomics Analysis Of Fecal Microbiota In Patients With Major Depressive Disorder

Major depressive disorder(MDD)is a highly widespread and debilitating mental illness,which is associated with disorder of gut microbiota.However,few studies focusing on detecting the signatures of bacteria in feces of MDD patients using proteomics approach have been conducted.Here,comparative metaproteomics analysis was performed to explore signature of gut microbiota in patients with MDD.Ten patients(ages 18-56 years,5 female)who had major depressive disorder and a score over 20 on the Hamilton's Depression Scale and 10 healthy control subjects(HCs)(ages 24-65 years,5 female)group-matched with gender,age,and body mass index(BMI)were enrolled.As a result,279 significantly differentiated bacterial proteins(P<0.05)were detected and used for further bioinformatic analysis.According to phylogenetic analysis,statistically significant differences were observed for four phyla-Bacteroidetes,Proteobacteria,Firmicutes,Actinobacteria(P<0.05,for each).Abundances of sixteen bacterial families were significantly different between the MDD and HCs(P<0.05).Furthermore,COGs category analysis and KEGG pathway analysis showed that disordered metabolic pathways of bacterial proteins were mainly involved in glucose metabolism and amino acid metabolism.In short,features of fecal microbiota were changed remarkably in MDD patients.Our findings provide a novel insight into the potential connection between gut microbiota and depression.