The result will be welcomed by infant formula-makers as there is increasing interest in using prebiotic ingredients in infant and follow-on formulas, on both sides of the Atlantic.
Researchers have found that breast milk naturally contains oligosaccharides, believed to stimulate bifidobacteria - so-called 'friendly' bacteria that help release energy and nutrients from food.
This has led to formula-makers adding prebiotics to their formulas in an attempt to match the prebiotic content of breast milk. While most prebiotic infant formulas are reported to be still in the development phase, some products have been launched into the market place.
The researchers of the new study, led by Professor Guenther Boehm from Numico Research, recruited 206 newborns at the Macedonio Melloni Maternity Hospital in Italy at risk of eczema (mothers had a history of eczema) and who were not being breast-fed by their mothers.
The babies were randomly assigned to receive either a prebiotic-enriched infant formula (0.8 grams per 100 mL of galacto-oligosaccharides (90 per cent) and fructo-oligosaccharides (10 per cent)) or a placebo infant formula (0.8 grams per 100 mL of matlodextrin) in a prospective, double-blind controlled trial.
The formula feeding was started at the age of six weeks and continued until six months of age. Check-ups were performed on a monthly basis and parents were asked to keep a symptoms diary.
Over the six months of the trial, only 10 babies in the prebiotics groups developed eczema (9.8 per cent), while this figure was more than double in the placebo group (24 infants, 23.1 per cent of the group).
Eczema, also known as atopic dermatitis (AD), is one of the first signs of allergy during the early days of life and is said to be due to delayed development of the immune system. According to the American Academy of Dermatologists it affects between 10 to 20 percent of all infants, but almost half of these kids will 'grow out' of eczema between the ages of five and 15.
A sub-set assessment of the faeces of 98 babies across the two groups showed that the infants receiving prebiotic formula had a significantly higher number of faecal bifidobacteria but no significant difference in the number of lactobacilli counts, compared to controls, report the researchers in the British Medical Association's Archives of Disease in Childhood (on-line ahead of print: doi: 10.1136/adc.2006.098251).
This, said Professor Boehm and his co-workers, shows that the prebiotics work by altering the intestinal flora of the infants.
"To our knowledge, this is the first report showing that prebiotic oligosaccharides can influence the incidence of atopic dermatitis," wrote the researchers.
The mechanism behind the benefits is not fully understood, said Professor Boehm and his co-workers. Previous research has shown that human milk oligosaccharides (HMOS) can affect cytokine production, pro-inflammatory molecules, in vitro.
"Thus, HMOS could serve as anti-inflammatory components of human milk and contribute to the lower incidence of inflammatory diseases such as necrotising enterocolitis in breast fed versus formula fed infants," they said.
The researchers called for further studies to complete the understanding the mechanism behind the benefits and how the prebiotics could affect immune function.
"The data support the potential role of prebiotics as dietary manipulation for primary allergy prevention during infancy," concluded the authors.
Prebiotic ingredients are currently worth €87m in the European marketplace and they are set to reach €179.7m by 2010, according to Frost & Sullivan.