Early Probiotics to Prevent Eczema or Asthma? No Luck So Far

William T. Basco, Jr., MD


December 13, 2017

A Trial of Probiotics to Prevent Atopic Disease in Children

Probiotics are live micro-organisms that, when administered in adequate amounts, confer a health benefit on the host.[1] The data on whether the administration of probiotics to either pregnant moms or infants can reduce later atopic outcomes in these children is unclear.

A recent study[1] tested the hypothesis that supplementing infants with probiotics during the first 6 months of life would reduce the incidence of eczema in children prone to atopic disease. Secondary outcomes included a hypothesized reduction in the incidence of asthma or allergic rhinitis. Study children were enrolled from 2006 to 2012 in the San Francisco area. The infants were all randomly assigned within 4 days of birth, and only newborns with at least one biological parent with asthma were included.

Intervention infants received a daily capsule that contained 10 billion colony-forming units of Lactobacillus rhamnosus GG and 225 mg of inulin for the first 6 months of life. Control infants received a similar capsule that contained only the inulin vehicle. Caregivers would open the capsule and dissolve the contents into breastmilk or formula and give it to the infants using a syringe to verify that they received it.

Formula was provided to the non-breastfeeding women, but those formulas did not contain probiotic or prebiotic supplementation.

The primary outcome of interest was a diagnosis of atopic dermatitis by the child's second birthday. The frequency of an asthma or allergic rhinitis diagnosis by age 5 years was also assessed. The infants were followed with multiple physical examinations during the first year of life as well as at age 2 years, and the families were followed more often by phone. Data on feeding practices, parental medical history, household characteristics, and many other potential confounders were collected at enrollment and during the study.

Study Findings

The final cohort included 184 infants who had been randomly assigned to either the probiotic or control group. Approximately 10% fallout occurred from each group, but overall 95% of the infants were followed through their second birthday. The sample was largely white (>80%), but more than 20% were of Hispanic ethnicity. Approximately 20% of the children had no breastmilk exposure.

Although L rhamnosus GG supplementation appeared to have some beneficial effects at the time of the 6-month evaluation, the outcomes were very similar between the two groups by their second birthdays, when 30.9% of the control children and 28.7% of the intervention children had developed eczema. This corresponded to a hazard ratio of 0.95 (95% confidence interval, 0.59-1.53). The incidence of asthma at age 5 years was 17.4% among the control group and 9.7% among the intervention group, but these confidence intervals overlapped, suggesting a lack of statistical significance. The investigators concluded that L rhamnosus GG supplementation in the first 6 months of life did not prevent eczema or asthma among these high-risk infants.


These findings are certainly disappointing because any approach that would reduce asthma among children would be of huge benefit to patients and healthcare providers given that asthma is the most common chronic condition of childhood. That said, the investigators pointed out some potential issues with their study that suggest that this is not the final word on whether L rhamnosus GG supplementation may help with atopy. First, this was a highly breastfed population, and breastfeeding may supersede benefit from probiotic supplementation. A question was also raised about whether prenatal supplementation combined with postnatal supplementation of the infant might prove more effective. In the meantime, it's good to know that there were no adverse events from the supplementation, and practitioners can feel comfortable that L rhamnosus GG probiotics are safe if parents inquire about them. However, evidence of efficacy remains elusive.


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