Kate Johnson

November 25, 2014

ATLANTA — Probiotics should be consumed by pregnant and lactating women and their breast-fed infants to prevent the development of atopic dermatitis, according to recommendations that will soon be issued by the World Allergy Organization.

"It will be the first time that probiotics will be recommended for allergy prevention by a medical organization," said Alessandro Fiocchi, MD, from the Pediatric Hospital Bambino Gesù in Rome. He made the announcement here at the American College of Allergy, Asthma & Immunology (ACAAI) 2014.

The Guidelines for Allergic Disease Prevention are still officially under review. The first section, on probiotics, is scheduled to be released at the end of January 2015, Dr. Fiocchi told Medscape Medical News. Sections on vitamin D and prebiotics will follow.

The probiotic recommendation relates only to atopic dermatitis. "I remain skeptical about the possibility that probiotics can prevent allergy," said Dr. Fiocchi, who delivered a plenary lecture on the subject.

In the meta-analysis of 29 studies, the consumption of probiotics by pregnant women had no effect on childhood asthma during a 2- to 7-year follow-up period (relative risk [RR], 0.97; 95% confidence interval [CI], 0.77 - 1.22), or on the development of food allergy during a 1- to 2-year follow-up period (RR, 1.08; 95% CI, 0.73 - 1.59). Consumption did, however, lead to a 9% reduction in eczema during a 1- to 5-year follow-up period (RR, 0.72; 95% CI, 0.6 - 0.86), Dr. Fiocchi reported.

Less Eczema

No effect of probiotic consumption by lactating women was demonstrated for childhood asthma during a 1- to 4-year follow-up, or for the development of food allergy during a 2- to 4-year follow-up. But there was a 16% reduction in eczema during a 6-month follow-up period (RR, 0.58; 95% CI 0.47 - 0.72).

For breast-feeding infants consuming probiotics, there was a 5% reduction in eczema during the 6-month to 6-year follow-up (RR, 0.82; 95% CI, 0.70 - 0.96), but no protection against asthma during a 9-month follow-up or the development of food allergy during a 1- to 6-year follow-up.

Despite "a general understanding that the strain of probiotic may be an important factor in preventive efficacy," it was "completely impossible" for the analysis to break down probiotic use according to strain, said Dr. Fiocchi.

He pointed out that recommendations on allergy prevention are urgently needed from medical organizations.

"Previous studies have supported avoidance of tobacco smoke as the only evidence-based research for primary avoidance for allergies and asthma," said James Sublett, MD, who is president-elect of the ACAAI.

Probiotics appear not only to modulate T-cells and cytokine profile, but also to help accelerate recovery of barrier function.

Their absence "leaves the field open to third-party interests who, completely skipping the rigors of scientific investigation, can directly target consumers with inappropriate claims," Dr. Fiocchi said.

"I think this matter must be owned by allergists through the powerful instrument of GRADE recommendations," which stands for Grading of Recommendations, Assessment, Development, and Evaluation, he explained.

The expected probiotic recommendations are exciting, said Peter Lio, MD, from the Northwestern University Feinberg School of Medicine in Chicago. However, "lumping the probiotics together may be deeply flawed."

"Specific strains or combinations of strains may be critical for certain effects, and this approach risks completely missing those. It may be akin to trying to study antibiotics as a class, without paying attention to the type of antibiotic or the dosage," he told Medscape Medical News.

"I feel that they may be being a little bit too reductionist by not considering strains or dosage regimens enough, and thus could dismiss an entire category of treatment unfairly," he said.

"Consolidated data show that probiotics are associated with a reduction of 20% to 25% in the incidence of pediatric atopic dermatitis," said Katherine Baquerizo Nole, MD, from the University of Miami Miller School of Medicine.

"Probiotics appear not only to modulate T-cells and cytokine profile, but also to help accelerate recovery of barrier function," she told Medscape Medical News. "Some effects seem to be strain-specific, which could explain the varied results among different research groups," she added.

"It seems that the best effect is achieved when prenatal administration is followed by postnatal administration, and the strains that showed the more consistent results are Lactobacillus and Bifidobacterium. The long-term benefits in atopic dermatitis prevention are still unclear."

Dr. Fiocchi reports relationships with Boehringer Ingelheim, Chiesi Farmaceutici, Stallergenes, Danone, and Valeas. Dr. Sublett reports relationships with Aerocrine, Asthmapolis, AstraZeneca, Forest, Genentech, GlaxoSmithKline, Meda, Merck, Sunovion, and Teva, and owning stock in AllergyZone. Dr. Lio reports relationships with Anacor, Galderma, Johnson & Johnson, Pierre Fabre Derm, Mission Pharmacal, and the Atopic Derm Foundation. Dr. Baquerizo Nole has disclosed no relevant financial relationships.

American College of Allergy, Asthma & Immunology (ACAAI) 2014. Presented November 9, 2014.


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