An increasing number of studies have documented associations between psychiatric diseases and the gut microbiome. By taking genetic correlation and comorbidity of different psychiatric diseases into consideration, we hypothesized that different psychiatric diseases might share some similar microbial shift patterns. However, a deep understanding of whether and how those psychiatric disease-associated microbial dysbiosis spectrums are correlated is currently lacking.
In this study, we analyzed six case-control 16S amplicon sequencing datasets for psychiatric disorders, which included a total of 430 subjects, and compared microbial dysbiosis patterns across these studies.
Different psychiatric diseases exhibited similar overall shift patterns. Significant correlations of overall shift patterns existed between schizophrenia and anorexia (p = 0.0008), as well as between schizophrenia and autism (p = 0.028). We identified 6 genera within order Clostridiales (genus Gemmiger, Faecalibacterium, Roseburia, Lachnospira, Anaerostipes, and two unclassified genera from family Lachnopsiraceae and Christensenellaceae) that were significantly depleted in multiple psychiatric diseases. Our further functional analysis revealed that depletion of these Clostridiales was associated with dysfunction in amino acid metabolism and carbohydrate metabolism. Short chain fatty acid (SCFA) producing bacteria Roseburia was the most important contributor for major KEGG (Kyoto Encyclopedia of Genes and Genomes) orthology entries involved in amino acid metabolism.
Our study revealed common microbial shift patterns across psychiatric disorders and found predominant psychiatry-associated intestinal microbes and functions. Depletion of Clostridiales (e.g., Roseburia) probably mediated different psychiatric diseases by dysfunction of intestinal amino acid metabolism and SCFA production. Furthermore, our study indicated that correlations of microbial shift patterns between psychiatric diseases may derived from their genetic associations. Such shared microbial dysbiosis patterns are intriguing for discovering biomarkers and investigating therapeutic targets for treating psychiatric diseases.

Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.