Hay Fever, Birch Pollen Allergy
Conditions
Brief summary
In vitro studies reveal immunomodulatory effects of probiotic bacteria that are strain-dependent. Differential immunomodulatory in vitro capacities can not be extrapolated directly to in vivo efficacy. Thus, in vitro screening should be followed by comparative analysis of the selected immunomodulatory probiotic strains in an in vivo setting. Birch pollen allergy is one of the most common forms of respiratory allergy in European countries, and recognized by a Th2-skewed immune system. Five Lactobacillus strains will be evaluated for their immunomodulatory properties in birch pollen sensitive subjects outside the hay fever season. A double-blind placebo-controlled parallel study will be performed in which subjects with a proven birch pollen allergy will consume one of 5 different probiotic yoghurts containing 4 L. plantarum strains and 1 L. casei strain or a placebo yoghurt. Blood samples are collected at the start and after 4 weeks. Immune parameters are determined in serum and peripheral blood mononuclear cell cultures (hPBMC) derived from these subjects.
Interventions
DIETARY_SUPPLEMENTYoghurt with L. plantarum strain
Intake of yoghurt during 4 weeks
DIETARY_SUPPLEMENTYoghurt with L.casei
Intake of yoghurt during 4 weeks
DIETARY_SUPPLEMENTYoghurt
Intake of yoghurt during 4 weeks
Sponsors
Allergologiepraktijk Arnhem/Radboud/Rijnstate
NIZO Food Research
Wageningen University
Campina Innovation
Rijnstate Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* birch pollen sensitive subjects * Positive RAST or intracutane skintest * age 18-50 * signed informed consent form
Exclusion criteria
* use of probiotics * known allergy for pets (home setting) * use of medication influencing the immune system * use of antibiotics * lactose intolerance * pregnancy * infection
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Il-13 in PBMC after ex-vivo stimulation with birch pollen allergen (Betv1) | — |
Secondary
| Measure | Time frame |
|---|---|
| Other cytokines and cell-surface markers in PBMC ex vivo stimulation assay, birch pollen specific IgE, IgG and IgG4 in blood | — |
Countries
Netherlands
Outcome results
None listed