HELSINKI, Finland—Childhood allergies have increased in industrialized countries during the past few decades, and researchers theorize it is a result of lowered exposure to bacteria in early childhood.
A recent study from the University Central Hospital of Helsinki reveals no allergy-preventive effect is extended to age 5 by perinatal supplementation with probiotics in babies at risk for developing allergies, but protection is conferred only to Cesarean section babies. The study, published in the Journal of Allergy and Clinical Immunology, observed that infants who develop allergies have intestinal bacteria that are distinctly different from those of non-allergic infants, suggesting that the type of intestinal microflora is an important factor in forming allergic conditions.
The clinical trial involved more than 1,200 mothers whose infants would be at high risk of developing allergies. During the last month of their pregnancies, the mothers took daily doses of a probiotic mixture or a placebo, and their infants were given the same probiotic mixture plus a prebiotic or a placebo for the first six months of their lives. The children were followed for five years and evaluated for incidence of allergic diseases.
Researchers found that the frequencies of allergic and IgE-associated allergic disease and sensitization were similar in the children who had received probiotics and those who received placebos. Although there appeared to be a preventive effect at age 2, there was none noted at age 5. Researchers found less IgE-associated allergic disease in babies born by Caesarian than those who received the probiotic.