Effect of a Mixture of Probiotics on the Antigen Specific Antibody Response in a Influenza Vaccination Model of Healthy Adults

Inclusion Criteria: * healthy male and female adult * between 18 and 60 years old non menopausal female( with effective contraception) * female non pregnant- not wishing to be pregnat during the study capable to respect the protocol * affialted to the social security system aggreeing to be registered in the national fileof volunteers Exclusion Criteria: * food allergy( component of the experimental product- vaccines) * manifestation of allergy * vaccinated against flu during the 2 previous winters * Food allergy, allergy to one of the component of the experimental products or allergy to one of the component of the flu vaccine; * Subject displaying manifestation of allergy or being treated for these; * Subject vaccinated against flu during the 2 previous winter (winter 2009-2010 and winter 2010-2011); * Subject who had symptoms evocating flu during the previous winter (winter 2010-2011); * Subject immunodepressed; * Subject with immunomodulatory treatment; * Subject who received a treatment resulting in systemic immunossuppression or local immunosuppression at pulmonary level, for at least 1 week during the last 3 months before inclusion (V1); * Subject with auto-immune disease; * Subject with inflammatory and chronic diseases; * Subject with on-going antibiotics treatment at the time of the inclusion; * Subject not agree to stop his/her usual probiotics supplementation during the study; * Use of medication which could interfere with the study in the investigator's opinion (antibiotics, etc…); * Any health condition for which the influenza vaccine is not recommended; * Subject having received any other vaccine within one month prior to enrolment or intent to receive any other vaccination during the study period.