Immune Benefits of WGP in Elderly

Inclusion Criteria: * Male and female elderly volunteers equal or above age of 70 * Pre-frail and frail subjects (based on Fried's criteria) * Willing to be vaccinated against influenza and having no contraindication to receive influenza vaccination * Having obtained his/her (or his/her legal representative's) informed consent Exclusion Criteria: * Subject with a rapidly deteriorating health status (terminal, severe, or uncontrolled acute/chronic diseases) * Allergy to eggs or influenza vaccine components. * Subject who has received any vaccination in the last 3 months or has previously been vaccinated with the current seasonal influenza vaccine. * Subject who is currently taking, or has taken in the last 4 weeks, or will take immune modulating medication during the study, including steroid, immune suppressive treatment. * Subject who has taken antibiotics in the last 2 months prior to entering the study. * Subject who is consuming regularly prebiotic and/or probiotic supplements, yogurts, and/or other dietary supplements. * Personal or family history of Guillain-Barre syndrome * BMI\>35 kg/m2 * Subject who has received blood transfusion or had a blood donation during the last 4 weeks prior to the beginning of this study. * Subject who cannot be expected to comply with the study procedures * Currently participating or having participated in another clinical trial during the last 4 weeks prior to the beginning of this study