Pilot Study on Effect Size of Non-digestible Polysaccharides (NPS) on Immunity

Inclusion Criteria: * Free-living postmenopausal woman and men aged ≥ 50 years willing to have influenza vaccination season 2012/2013 * willingness to abstain as far as possible from food and supplements containing probiotics, prebiotic supplements, other fermented products, supplements containing vitamins and minerals as well as willing to sustain on a low dietary fibre diet for 7 weeks. * written informed consent Exclusion Criteria: * Subjects enrolled in another clinical study in the last 4 weeks * Subjects already vaccinated against influenza during 2012-2013 with either the influenza vaccine used in the present study or another influenza vaccine * vaccination against influenza within the previous 10 months * suffering from influenza or influenza-like illness within the previous 10 months * other vaccinations during and within 2 months before the study * symptoms of common infectious diseases (CID) of the airways or other organ systems e.g. gastrointestinal tract in the last 4 weeks before inclusion * known congenital, acquired or iatrogenic immunodeficiency (e.g. HIV, chemotherapy, immunosuppression) * active autoimmune diseases * allergy or hypersensitivity to any component of the vaccine (e. g. chicken egg protein, certain antibiotics)(s. a. 9.2) * allergy or hypersensitivity to any component of the test product (e. g. yeast, gluten, shiitake mushrooms) * allergy to latex * known coeliac disease (gluten enteropathy) * bowel movement less than 3 times per week * subjects, who meet 2 or more Rome III criteria for constipation or who take laxatives on a regular basis * severe chronic disease (cancer, IBD, malabsorption, malnutrition, chronic inflammatory diseases, renal, hepatic or cardiac diseases, COPD, respiratory insufficiency) * chronic abdominal pain * malformation of fingers * systemic treatment or topical treatment likely to interfere with evaluation of the study parameters: antibiotics, intestinal or respiratory antiseptics, anti-rheumatics, antiphlogistics (except aspirin or equivalent products preventing from aggregation of platelets or blood clotting) and steroids prescribed in chronic inflammatory diseases * other treatments likely to interfere with study outcome (e.g. laxatives, body weight management and/or medication) * treatments with calcium antagonists and nitrates and alpha blockers * diabetes mellitus on drug therapy * severe neurological, cognitive or psychiatric diseases * surgery or intervention requiring general anaesthesia within 2 months before the study * vegetarian, vegan * eating disorders (e.g. anorexia, bulimia) * alcohol and drug abuse * pregnancy or lactation * legal incapacity * blood parameters: Hb \< 12 g/dL Liver transaminases (ALT, AST) \> 2-fold increased Serum creatinine \> 1,2 mg/dL