Probiotics and Influenza Vaccination Response

Effects of Probiotics in Immune Response to Influenza Vaccination in Adults

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 women
• Age 16 - 65 y and healthy
• Self-reported regular Dutch eating habits as assessed by questionnaire (3 main meals per day)
• No influenza vaccination in 2022
• Non-smokers
• BMI 18.5-28
• Adherence to habitual diet
• no changes during study period
• Signed informed consent

Exclusion Criteria:

• Recent vaccination
• Acute or chronic illness (e.g., diabetes mellitus)
• Gastrointestinal disorders (e.g., inflammatory bowel disease)
• Acute gastroenteritis in the past 2 months
• Immunodeficiency disorder
• Use 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 screening
• Alcohol or drug abuse
• Mental status that is incompatible with the proper conduct of the study
• History of cancer
• Use of immune boosting supplements within 4 weeks before screening To be extended & specified in protocol phase