Probiotics and Influenza Vaccination Response

Assess efficacy of oral ingestion of a probiotic product on immune function in a population of healthy adult men and women in a clinical vaccination study.

Inclusion Criteria:Men and womenAge 16 - 65 y and healthySelf-reported regular Dutch eating habits as assessed by questionnaire (3 main meals per day)No influenza vaccination in 2022Non-smokersBMI 18.5-28Adherence to habitual dietno changes during study periodSigned informed consentExclusion Criteria:Recent vaccinationAcute or chronic illness (e.g., diabetes mellitus)Gastrointestinal disorders (e.g., inflammatory bowel disease)Acute gastroenteritis in the past 2 monthsImmunodeficiency disorderUse of immunosuppressive drugs (e.g. cyclosporine, azathioprine, systemic corticosteroids, antibodies)Unexplained weight loss or weight gain of > 3 kg in the 3 months prior to pre-study screeningAlcohol or drug abuseMental status that is incompatible with the proper conduct of the studyHistory of cancerUse of immune boosting supplements within 4 weeks before screening To be extended & specified in protocol phase