Authors: Andrea Fontana, Mirko Manchia, Concetta Panebianco, Pasquale Paribello, Carlo Arzedi, Eleonora Cossu, Mario Garzilli, Maria Antonietta Montis, Andrea Mura, Claudia Pisanu, Donatella Congiu, Massimiliano Copetti, Federica Pinna, Bernardo Carpiniello, Alessio Squassina, Valerio Pazienza

Institutions: 

  • Fondazione IRCCS Casa Sollievo della Sofferenza Hospital, Unit of Biostatistics, 71013 San Giovanni Rotondo, Italy
  • Unit of Psychiatry, Department of Public Health, Clinical and Molecular Medicine, University of Cagliari, 09042 Cagliari, Italy
  • Unit of Clinical Psychiatry, University Hospital Agency of Cagliari, 09042 Cagliari, Italy
  • Department of Pharmacology, Dalhousie University, Halifax, NS B3H 4R2, Canada
  • Fondazione IRCCS Casa Sollievo della Sofferenza Hospital, Division of Gastroenterology, 71013 San Giovanni Rotondo, Italy
  • Unit of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, 09042 Cagliari, Italy
  • Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University Campus, S.P. 8, Sestu-Monserrato, Km 0.700, Monserrato, 09042 Cagliari, Italy
  • Gastroenterology Unit, Fondazione I.R.C.C.S. “Casa Sollievo della Sofferenza” Hospital, Viale dei Cappuccini 1, 71013 San Giovanni Rotondo, Italy

Publication: Biomedicine

Date: July 2020

Full paper: Exploring the Role of Gut Microbiota in Major Depressive Disorder and in Treatment Resistance to Antidepressants

Abstract:

Major depressive disorder (MDD) is a common severe psychiatric illness, exhibiting sub-optimal response to existing pharmacological treatments. Although its etiopathogenesis is still not completely understood, recent findings suggest that an altered composition of the gut microbiota might play a role. Here we aimed to explore potential differences in the composition of the gut microbiota between patients with MDD and healthy controls (HC) and to identify possible signatures of treatment response by analyzing two groups of MDD patients characterized as treatment-resistant (TR) or responders (R) to antidepressants. Stool samples were collected from 34 MDD patients (8 TR, 19 R and 7 untreated) and 20 HC. Microbiota was characterized using the 16S metagenomic approach. A penalized logistic regression analysis algorithm was applied to identify bacterial populations that best discriminate the diagnostic groups. Statistically significant differences were identified for the families of Paenibacillaceae and Flavobacteriaceaea, for the genus Fenollaria, and the species Flintibacter butyricus, Christensenella timonensis, and Eisenbergiella massiliensis among others. The phyla Proteobacteria, Tenericutes and the family Peptostreptococcaceae were more abundant in TR, whereas the phylum Actinobacteria was enriched in R patients. Moreover, a number of bacteria only characterized the microbiota of TR patients, and many others were only detected in R. Our results confirm that dysbiosis is a hallmark of MDD and suggest that microbiota of TR patients significantly differs from responders to antidepressants. This finding further supports the relevance of an altered composition of the gut microbiota in the etiopathogenesis of MDD, suggesting a role in response to antidepressants.