Domènech Salgado, Laura, 1989-Willis, Jesse R.Alemany-Navarro, MaríaMorell, MartaReal, EvaEscaramís, GeòrgiaBertolín, SaraSánchez Chinchilla, DanielBalcells, SusanaSegalàs, CintoEstivill, Xavier, 1955-Menchón, José M.Gabaldón Estevan, Juan Antonio, 1973-Alonso, PinoRabionet, Raquel2022-04-202022-04-202022Domènech L, Willis J, Alemany-Navarro M, Morell M, Real E, Escaramís G, Bertolín S, Sánchez Chinchilla D, Balcells S, Segalàs C, Estivill X, Menchón JM, Gabaldón T, Alonso P, Rabionet R. Changes in the stool and oropharyngeal microbiome in obsessive-compulsive disorder. Sci Rep. 2022 Jan 27;12(1):1448. DOI: 10.1038/s41598-022-05480-92045-2322http://hdl.handle.net/10230/52854Although the etiology of obsessive-compulsive disorder (OCD) is largely unknown, it is accepted that OCD is a complex disorder. There is a known bi-directional interaction between the gut microbiome and brain activity. Several authors have reported associations between changes in gut microbiota and neuropsychiatric disorders, including depression or autism. Furthermore, a pediatric-onset neuropsychiatric OCD-related syndrome occurs after streptococcal infection, which might indicate that exposure to certain microbes could be involved in OCD susceptibility. However, only one study has investigated the microbiome of OCD patients to date. We performed 16S ribosomal RNA gene-based metagenomic sequencing to analyze the stool and oropharyngeal microbiome composition of 32 OCD cases and 32 age and gender matched controls. We estimated different α- and β-diversity measures and performed LEfSe and Wilcoxon tests to assess differences in bacterial distribution. OCD stool samples showed a trend towards lower bacterial α-diversity, as well as an increase of the relative abundance of Rikenellaceae, particularly of the genus Alistipes, and lower relative abundance of Prevotellaceae, and two genera within the Lachnospiraceae: Agathobacer and Coprococcus. However, we did not observe a different Bacteroidetes to Firmicutes ratio between OCD cases and controls. Analysis of the oropharyngeal microbiome composition showed a lower Fusobacteria to Actinobacteria ratio in OCD cases. In conclusion, we observed an imbalance in the gut and oropharyngeal microbiomes of OCD cases, including, in stool, an increase of bacteria from the Rikenellaceae family, associated with gut inflammation, and a decrease of bacteria from the Coprococcus genus, associated with DOPAC synthesis.application/pdfeng© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/s41598-022-05480-9BiomarkersObsessive compulsive disorderinfo:eu-repo/semantics/openAccess