title: Behçet's syndrome patients exhibit specific microbiome signature.
abstract: OBJECTIVE
  Behçet syndrome is a systemic inflammatory condition characterized by muco-cutaneous and ocular manifestations, with central nervous system, vascular and/or gastro-intestinal involvement. The association of microbiota with Behçet syndrome has not been shown yet. Our work was aimed to compare the gut microbiota structure and the profiles of short-chain fatty acids production in Behçet syndrome patients and healthy control relatives.
  
  
  METHODS
  Here, we compared the fecal microbiota of 22 patients with Behçet syndrome and that of 16 healthy co-habiting controls, sharing the same diet and lifestyle by pyrosequencing of the V3-V4 hypervariable regions of the 16 rDNA gene and biochemical analyses.
  
  
  RESULTS
  Our analyses showed significant differences in gut microbiota between Behçet patients and healthy cohabitants. In particular we found that Behçet's patients were significantly depleted in the genera Roseburia and Subdoligranulum. Roseburia showed a relative abundance value of 10.45±6.01% in healthy relatives and 4.97±5.09% in Behçet's patients, and Subdoligranulum, which reached a relative abundance of 3.28±2.20% in healthy controls, was only at 1.93±1.75% of abundance in Behçet's patients. Here we report, for the first time, that a peculiar dysbiosis of the gut microbiota is present in patients with Behçet syndrome and this corresponds to specific changes in microbiome profile. A significant decrease of butyrate production (P=0.0033) in Behçet's patients was demonstrated. Butyrate is able to promote differentiation of T-regulatory cells, and consequently the results obtained prompt us to speculate that a defect of butyrate production might lead to both reduced T-reg responses and activation of immuno-pathological T-effector responses.
  
  
  CONCLUSIONS
  Altogether, our results indicate that both a peculiar dysbiosis of the gut microbiota and a significant decrease of butyrate production are present in patients with Behçet syndrome.
authors.affiliation: Institute of Biomedical Technologies, National Research Council (ITB-CNR), Segrate, Milan, Italy. Electronic address: clarissa.consolandi@itb.cnr.it.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Consolandi
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Turroni
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Emmi
authors.affiliation: Institute of Biomedical Technologies, National Research Council (ITB-CNR), Segrate, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Severgnini
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Jessica
authors.initials: J
authors.lastname: Fiori
authors.affiliation: Institute of Biomedical Technologies, National Research Council (ITB-CNR), Segrate, Milan, Italy.
authors.forename: Clelia
authors.initials: C
authors.lastname: Peano
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Biagi
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Grassi
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Rampelli
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Silvestri
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Centanni
authors.affiliation: Department of Surgery and Translational Medicine, University of Florence, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Cianchi
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Gotti
authors.affiliation: Medical Pathology, Center for Autoimmune Systemic Diseases, Behçet Center and Lupus Clinic, AOU Careggi, Florence, Italy. Electronic address: lorenzoemmi@yahoo.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Emmi
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Brigidi
authors.affiliation: Laboratory of Clinical Pathology, Diagnostic Department, San Antonio Hospital, Tolmezzo, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Bizzaro
authors.affiliation: Institute of Biomedical Technologies, National Research Council (ITB-CNR), Segrate, Milan, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: De Bellis
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Medical Pathology, Center for Autoimmune Systemic Diseases, Behçet Center and Lupus Clinic, AOU Careggi, Florence, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Prisco
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Candela
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Medical Pathology, Center for Autoimmune Systemic Diseases, Behçet Center and Lupus Clinic, AOU Careggi, Florence, Italy.
authors.forename: Mario M
authors.initials: MM
authors.lastname: D'Elios
mesh_terms: D000328:Adult; D001528:Behcet Syndrome / Q000382:microbiology* / Q000473:pathology; D064806:Dysbiosis / Q000473:pathology; D005227:Fatty Acids / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D064307:Microbiota
chemical_list: D005227:Fatty Acids
keywords: Behçet; Gut microbiota; Immune system response; Pyrosequencing