The current study aims to explore a range of possible pathways by which BSCU1 could beneficially modulate the immune system, in three target populations representing the general population.

This exploratory study is designed as a single-arm study with repeated measures, involving three different populations, in which each subject serves as its own control. The duration of the intervention is 4 weeks, with biomarker assessments at baseline, after 2 weeks, and after 4 weeks intervention.

Inclusion Criteria:

Adults

• 30 ≤ age ≤ 49 years
• BMI ≥ 18.5 and ≤ 25 kg/m2
• In good health as assessed during screening (by questionnaire), and the medical investigator's professional judgment
• Non-smoking

Elderly

• 65 ≤ age ≤ 79 years
• BMI ≥ 22.0 and ≤ 28.0 kg/m2
• Generally healthy as assessed during screening (by questionnaire), and the medical investigator's professional judgment
• Non-smoking

Children

• 3 ≤ age ≤ 6 years
• Healthy BMI, cut-off points will be used as indicated by JGZ
• Generally healthy as assessed during screening (by parental anamnesis), and the study physician's professional judgment

Exclusion Criteria:

Adults and elderly

• Chronic illness (e.g., diabetes mellitus, cardiac insufficiency, respiratory insufficiency, cancer, chronic kidney or liver disease),
• Acute infection in the past month
• Gastrointestinal disorders (e.g., inflammatory bowel disease),
• Acute gastroenteritis in the past 2 months
• Any vaccination in the past month or any scheduled vaccination during the study period
• Treatment with antibiotics within 2 months before the start of the study and during the study period
• Regular use of laxative agents
• Immunodeficiency disorder
• Use of anti-inflammatory or 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
• Regular consumption of probiotics within 1 month before start of the study
• Evidence of current excessive alcohol consumption (>4 consumptions/day or >20 consumptions/week) or drug (ab)use
• Mental status that is incompatible with the proper conduct of the study

Children

• Acute respiratory or gastrointestinal infection in the past month
• Chronic illness (e.g. chronic infections, systemic or metabolic disease)
• Gastrointestinal disorders (e.g., inflammatory bowel disease),
• Acute gastroenteritis in the past 2 months
• Any vaccination in the past month or any scheduled vaccination during the study period
• Treatment with antibiotics within 2 months before the start of the study and during the study period
• Immunodeficiency disorder
• Use of anti-inflammatory or immunosuppressive drugs (e.g.cyclosporine, azathioprine, systemic corticosteroids, antibodies)
• Regular use of laxative agents
• Regular consumption of probiotics within 1 month before start of the study