Intestinal microflora at 4 months of age and the development of allergy

Abstract

Because microflora has been reported to have an important effect on the development of allergic disorders, we measured intestinal microflora levels in 4-month-old infants and studied the development of allergic disorders. Blood samples from 18 4-month-old infants and 15 1-year-old infants were examined for total serum IgE and specific IgE antibodies. Stool samples from 18 4-month-old infants were examined for the presence of microflora. A positive correlation was observed between the ratio of breast-feeding at 1 month and the percentage of bifidobacteria in the intestine at 4 months (correlation ratio = 0.54; P = 0.022). Atopic dermatitis was observed in 12 of 18 infants at 4 months and in five of 15 infants at 1 year. Egg white-specific IgE was positive (≥ 0.70 UA/mL) in six infants at 4 months and in seven infants at 1 year. No relationship was observed between the percentage of bifidobacteria, lactobacilli or clostridia in the intestinal tract at 4 months and the development of allergy. However, all five infants who exhibited a percentage of bacter- oides (compared with the total intestinal microflora level) of more than 10% at 4 months had positive egg white-specific IgE and higher levels of total IgE (> 25 IU/mL) at 1 year; these relationships were statistically significant (P = 0.01). Colonization with bacteroides at 4 months of age is suggested to be related to the allergic state at 1 year of age.