Behçet's disease (BD) is a systemic vasculitis that affects, especially, young people.

Although its etiology remains unexplained, data suggest that the inflammatory response during BD results from a disruption of the homeostasis of innate and adaptive immune responses in genetically predisposed people. The microbiota could play a triggering role in BD, in particular the salivary and dental plaque microbiota. The aim of the Behçetbiot study is therefore to establish microbial profiles of dental plaque, pathological (on the mouth ulcer) and non-pathological mucous membrane, salivary and digestive and to compare them with control subjects not suffering from BD, related to the first degree, of the same socio-cultural level and to determine whether dysbiosis is correlated with a local and systemic pro-inflammatory response, by measuring salivary level of pro-inflammatory cytokines and blood level of CRP, fibrinogen, orosomucoïd and haptoglobin, and to compare them with controls.

All patients and their controls are sampled for stool, saliva, dantal plaque, oral mucosa, genital mucosa and blood during an annual follow-up visit or if they are hospitalised.

Plaque, oral mucosa, genital mucosa salivary and blood will be collected during an annual follow-up visit.

For stool samples, the collection material will be provided to the patient and they will be able to take the sample at home and bring it to the clinic, or send them via a carrier within 3 days.

All the samples related to the study will be taken in the internal medicine in Clermont-Ferrand (France) or Pitie Salpêtrière, department of internal medecine, Paris,France or ophthalmology departments in Clermont-Ferrand.

All sample will be stocked in biological center in Clermont-Ferrand before analyze.

Microbiota analyzes will be realise at M2iSH laboratoty, inflammatory cytokines will be analyze in Clermont-Ferrand immunology laboratory, and pro-inflammatory parameters will be analyse in biochimy laboratory in Clermont-Ferrand.

Inclusion Criteria:

• Patients who meet the International criteria for the classification of Behçet's disease, revised in 2013)
• Patient who had developed the disease in the 5 years preceding the study.

Exclusion Criteria:

• Pregnant or breastfeeding women, or women who may be pregnant or breastfeeding.
• Subject placed under judicial protection.
• Patient had received antibiotic or probiotic or symbiotic therapy in the 6 weeks preceding inclusion

Patient who have behçet's disease.

Data are reserved for M2ISH laboratory team .