Effect of a probiotic strain on immune response to influenza vaccinatio

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 100

Inclusion Criteria

1. Age >=16 and <=65
2. Self-reported regular Dutch eating habits as assessed by questionnaire (3
main meals per day)
3. Non-smokers (ex-smokers can participate if they stopped at least 6 months
before screening)
4. BMI >=18.5 and <=28
5. In good health as assessed during screening, and the medical investigator*s
professional judgment
6. Adherence to habitual diet, no changes during study period
7. Signed informed consent

Exclusion Criteria

1. Influenza vaccination within 6 months before the start of the intervention
2. Any vaccination in the month before randomization (visit 1) or any scheduled
vaccination during the study period
3. Self-reported influenza infection within 6 months before the start of the
intervention
4. Acute infection (including gastroenteritis) within 2 months before start of
the intervention
5. Treatment with oral antibiotics within 2 months before the start of the
intervention
6. Serious progressive disease or non-stabilized chronic illness (e.g.,
diabetes mellitus, cardiac insufficiency, respiratory insufficiency, cancer,
chronic kidney or liver disease)
7. Gastrointestinal disorders (e.g., inflammatory bowel disease)
8. Immunodeficiency or autoimmune disorder
9. Use of immunosuppressive drugs (e.g. cyclosporine, azathioprine, systemic
corticosteroids, antibodies)
10. Unexplained weight loss or weight gain of > 3 kg in the 3 months prior to
pre-study screening
11. Evidence of current excessive alcohol consumption (>4 consumptions/day or
>20 consumptions/week) or drug (ab)use
12. No change in use of immune boosting supplements during the study
13. Mental status that is incompatible with the proper conduct of the study

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The percentage of subjects with either a pre-vaccination HAI titer < 1:10 and a<br /><br>post-vaccination HAI titer >= 1:40 or a pre-vaccination HAI titer >= 1:10 and a<br /><br>minimum four-fold rise in post-vaccination HAI antibody titer.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>• Geometric Mean Titre of influenza-specific antibodies<br /><br>• Seroprotection<br /><br>• Change in plasma cytokines (IL-10, IL-4, and TNF-alpha, IFN-gamma)<br /><br>• Vaccine-specific plasma IgG concentrations<br /><br>• Plasma total IgG concentrations<br /><br>• Symptoms of respiratory tract infections (RTI)<br /><br>• Gastrointestinal symptoms<br /><br>• Adverse Events </p><br>