Primary Prevention of Allergic Disease in Early Child by Lactobacillus Reuteri

Study Overview
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Brief Summary
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An altered microbial exposure may be partly responsible for the increase of allergic diseases in populations with a western lifestyle. Activation of the immune system by microbes early in life is probably required for an accurate maturation of the immune system. Probiotics, live bacteria which are considered to confer health when ingested, have been suggested to prevent eczema and sensitisation infants. The aim of this study is to assess the effect of oral supplementation with the probiotic bacterium Lactobacillus reuteri in infancy on the development of allergic disease and sensitisation during the first 2 years of life and to examine mechanisms possibly underlying eventual effects on allergic manifestations. A follow up was performed at 7 years of age.

Detailed Description
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An altered microbial exposure may be partly responsible for the increase of allergic diseases in populations with a western lifestyle. Activation of the immune system by microbes early in life is probably required for an accurate maturation of the immune system. Probiotics, live bacteria which are considered to confer health when ingested, have been suggested to prevent eczema and sensitisation infants. The aim of this study is to assess the effect of oral supplementation with the probiotic bacterium Lactobacillus reuteri (L. reuteri) in infancy on the development of allergic disease and sensitisation during the first 2 years of life and to examine mechanisms possibly underlying eventual effects on allergic manifestations. In the study the development of allergic disease will also be related prospectively to immunological, nutritional and environmental factors. The study is a prospective double-blind placebo-controlled multicenter trial, comprising 232 families with allergic disease. The families are recruited at the antenatal clinic, and the mothers will receive L. reuteri ATCC 55730 (1 x 100 000 000 colony forming units, Biogaia AB, Stockholm, Sweden) or placebo daily from gestational week 36 until delivery. Their babies then will continue with the same study product from birth until 12 months of age and will be followed up for another year. Clinical follow-up will be done at 1, 3, 6,12 and 24 months of age and telephone interviews at 2,4,5, 8, 10 and 18 months. A questionnaire will be completed on each occasion. Skin prick test will be performed at 6, 12 and 24 months of age. Venous blood will be collected from the umbilical cord and at 6, 12 and 24 months and stored as heparinized plasma or serum until assessment. Peripheral mononuclear blood cells (PBMC) will be separated from the plasma samples before storage. Blood samples will also be collected from the mother and father once during the study. The stool sample will be collected from the mother during the 1 week after delivery and the infant at 5-7 days, 1 month, 3 months, 6 months, 12 months and 24 months of age. Saliva samples will be collected at 3, 6, 12 and 24 months of age and breast milk samples will be collected from the mother 1-3 days and 1 months after delivery. The saliva, breast milk and plasma/serum samples will be stored in -20°C and stool samples and the PBMC in -70°C until assessment. A follow up was performed at 7 years of age focusing on allergic disease. Spirometry, skin prick test was performed. Of the 188 completing the 2 year follow up, 184 also completed the 7 year follow up.

Official Title
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Primary Prevention of Allergic Disease in Early Child by Lactobacillus Reuteri

Conditions
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Allergic Conditions

Intervention / Treatment
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* Dietary Supplement: Lactobacillus reuteri
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant women with history of previous or present allergic disease in at least one member of the immediate family (parents or siblings). Expected compliance. Written informed consent obtained from parents. Exclusion Criteria: Insufficient compliance, i.e. a consumption of the study product below half of the expected.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br> | Dietary Supplement: Placebo<br>* The placebo consists of the same oil that the active study product but without any bacteria and is not possible to differentiate from the active product by smell, taste or visual appearance<br>|
| Active Comparator: Lactobacillus reuteri<br> | Dietary Supplement: Lactobacillus reuteri<br>* The mothers started taking Lactobacillus reuteri ATCC 55730 (BioGaia AB, Stockholm, Sweden) or placebo four weeks before term and continued to do so daily until delivery. After birth, the baby commenced with the same study product as the mother at 1-3 days of age and continued daily for one year. The daily intake, five oil droplets, corresponded to 1 x 100 000 000 colony forming units (CFU)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Allergic disease | Allergic disease was defined as any of the following: eczema, asthma, allergic rhinoconjunctivitis, allergic urticaria, gastrointestinal allergy. These diagnosis are based on predefined criteria. | Incidence until 2 years of age | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitization | Positive skin prick test and /or circulation IgE against allergen in blood | incidence until 2 years of age | 
| IgE-associated allergic disease | Allergic disease was classified as IgE-associated if the symptomatic infant also was sensitized | Incidence until 2 years of age | 
| Lactobacillus reuteri colonization in stool and breast milk | Isolation of Lactobacillus reuteri in stool and breast milk samples from the mother and infant with conventional and molecular methods. | Point prevalance until 2 years of age | 
| Cytokines in breast milk | Cytokines in breast milk from the mother will be measured by ELISA. | 1-3 days and 1 months postpartum | 
| Th1 and Th2- associated chemokines in blood samples | Th1 and Th2- associated chemokines will be analyzed in blood samples from the infant with ELISA and Luminex. | Development from birth until 2 years of age | 
| Microbial composition in stool samples | The microbial composition in stoll samples from the mothers and infants will be assessed with conventional cultivation and molecular microbiology methods | Development from birth until 2 years of age | 
| Allergic disease at 7 years of age | Allergic disease at 7 years of age was defined as any of the following: eczema, asthma, allergic rhinoconjunctivitis, allergic urticaria. These diagnosis are based on predefined criteria. | 2001-2011 | 
| Prevalence of caries in primary dentition at 8 years of age | Prevalence of caries in primary dentition is examined by dentists at 8 yeas of age. These diagnosis are based on predefined criteria. | 2009-2012 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Infants, Probiotics, Prevention, Lactobacillus reuteri, Eczema, IgE, Sensitization, Microbiota, Chemokines