Prebiotics Cut Atopic Dermatitis in High-Risk Infants

FRIEDRICHSDORF, Germany, July 27 -- Infant formula laced with prebiotic oligosaccharides modified bowel bacteria and more than halved the risk of atopic dermatitis among high-risk babies, researchers here reported.

In a double-blind, randomized, placebo-controlled trial of 259 infants at risk for atopy, over six months only 10 of 102 infants (9.8%; 95% CI 5.4-17.1%) given prebiotics in their formula developed atopic dermatitis according to an online report in the July Archives of Disease in Childhood. By contrast, 24 of 104 controls given normal formula (23.1%; CI 16.0-32.1%) developed the disorder.

Assessment of stool samples from 98 babies found a significantly higher number of fecal bifidobacteria in the prebiotic-fed infants compared with controls but no significant difference in lactobacilli counts, reported Guenther Boehm, M.D., of Numico Research here, a provider of funding for this study, and colleagues in Berlin, Italy, and The Netherlands.

Mothers and babies were seen at the Macedonio Melloni Maternity Hospital in Milan, and had a parental history of atopic eczema, allergic rhinitis, or asthma. Breast feeding was recommended to all the mothers, the researchers said, and 53 infants left the trial because their mothers wanted to re-establish breast feeding.

The prebiotic mixture used in this study (0.8g/100 mL) comprised 90% short-chain oligosaccharides and 10% long-chain fructo-oligosaccharides, a formula based on an analysis of oligosaccharides in human milk, Dr. Boehm said.

Human breast milk contains natural prebiotics that promote the growth of intestinal bacteria, such a lactobacilli and bifidobacteria. These, in turn, boost the development of an immune system that can help prevent allergies in a very young child, he said.

The intestinal flora are part of a complex ecosystem and many of its constituent bacteria remain unidentified. However, there is strong evidence that intestinal flora influence the postnatal development of the immune system. Stimulation of the entire intestinal flora by prebiotics might be a more effective method of altering immune development than by adding a single bacterial species to the intestinal ecosystem, Dr. Boehm and colleagues said.

The results of the present study do not allow conclusions about the mechanisms of the observed effects, the researchers said. The complexity of the structure of oligosaccharides in human milk indicates that breast feeding provides further support besides stimulation of the intestinal flora.

"Although further studies are needed to understand completely the mechanism behind the immune-modulating effect of the studied prebiotics, the data support the potential role of prebiotics as dietary manipulation for primary allergy prevention during infancy," Dr. Boehm and colleagues concluded.

The researchers wrote that the funding for the study was partially supported by a grant from Numico Research, Friedrichsdorf, Germany, and the EARNEST program (Food-CT-00678).