Influence of Probiotics on Prevention of Atopy, Atopic Disease and Immunological Responses

One of the most important early influences on the immune system is the intestinal microflora. The gastrointestinal tract, being the largest body area interacting with the environment, is one of the earliest to be colonized and is quantitatively the most important source of microbial stimulation for the immature immune system. Probiotics are helpful bacteria from healthy intestinal tract, and have shown potential in reducing allergy. This is extremely important as allergic diseases are on the rise worldwide. Probiotics are safe, easy to administer and can be used early for intervention as allergic sensitization, once established, is difficult to reverse.

This double-blind, randomized placebo-controlled study has recruited 253 children from birth. These babies, with a family history of atopic disease, will be randomly assigned into one of 2 groups to receive either normal infant formula or formula with Bifidobacterium longum and Lactobacillus rhamnosus GG. The formula will be consumed postnatally for 6 months, after which the child will continue with normal follow-on milk. Children will be examined at the neonatal period and at 1, 3, 6, 12 and 24 months. Blood samples will be collected at birth (cord blood) and at 1 year of age. Blood will be analyzed for cytokines, total IgE and specific IgE. Skin prick test for common allergens will also be performed at 1 year of age. Stools will be collected at 5 days, 1, 3, 12 months and analyzed for the pattern of stool colonization.

Inclusion criteria

• Parents agree to the subject's participation in the study and informed consent has been obtained.
• Either parent or sibling (i.e. first degree relative) has a history of atopy. This will be evidenced by a doctor-diagnosis of asthma, allergic rhinitis or eczema and a positive skin prick test to any of a panel of common allergens.
• The subject is born at above 35 weeks of gestation and weighs above 2 kg.
• The subject does not have major congenital malformations/major illness.
• Family appears to be able to successfully complete this trial.

Exclusion criteria

• Mother has a medical illness, which in the opinion of the investigator, will interfere with the results of the study.
• The parent is unable/unwilling to comply with procedures.
• The parents choose to totally breast-feed the child.