PURPOSE OF THE STUDY.
To study the effect of after-birth oral colonization by a probiotic Escherichia coli strain in infants of allergic mothers to reduce occurrence of allergy later in life.
There were 158 term breastfed infants followed from birth, 113 of whom were born to allergic mothers. Allergic mothers selected for the study met criteria that included clinical manifestation of allergy for more than 24 months, positive allergy-test results, and response to allergy treatment.
The infants were divided into groups of colonized infants of allergic mothers (56), control infants of allergic mothers (57), and control infants of healthy mothers (45). Infants of allergic mothers were randomly assigned to 1 of the first 2 groups. Incidence rates of bacterial pathogens in stool and levels of anti–E coli immunoglobulins and serum cytokines were determined, and secretory immunoglobulin A was monitored in stool filtrates and maternal milk. Clinical evaluation of infants aged 4 days, 3 and 6 months, and 1, 2, 3, and 5 years were carried out, and clinical symptoms of allergy were monitored. One milliliter of the probiotic E coli strain (0.8 × 109 lyophilized E coli, serotype O83:K24:H31) was administered orally to infants of allergic mothers within 48 hours after birth and subsequently 3 times per week over a period of 4 weeks. Control infants of allergic and healthy mothers were monitored in these intervals as well.
The E coli strain was not found in stool samples before its administration. At the 5-year conclusion of the study, allergy symptoms were found in 14 of 45 (31%) infants of control allergic mothers, 7 of 42 (16%) infants of healthy mothers, and 2 of 46 (4%) infants of allergic mothers who were colonized at birth with probiotic E coli. The incidence of allergy at 5 years was significantly lower in the colonized infants of allergic mothers compared with the infants of control allergic mothers (P < .001). The incidence reduction in the colonized group compared with that in the infants of healthy mothers was not significant. Allergic phenotype and higher interleukin 4 and 13 and lower interferon γ and transforming growth factor β levels dominated in the allergic group, but the values observed were not quantitatively different.
After birth, targeted colonization of the intestine by a probiotic E coli strain might be an effective means of allergy prevention for infants of allergic mothers.
As allergic diseases continue to increase in prevalence around the world, primary prevention of allergic disease has been elusive. Although previous studies have found that probiotics might be an effective intervention for eczema, there is little evidence to show that probiotics are beneficial for preventing other allergic diseases. With a significant reduction in clinical signs of overall allergies in the group treated with probiotics, the results of this study raise an interesting therapeutic option, although when examining the types of allergies that these children had, the effect seems to have been primarily for skin-related allergic disease. Further studies will need to evaluate the true effectiveness of these probiotics in allergy prevention.
- Copyright © 2011 by the American Academy of Pediatrics