Probiotics given to pregnant women and babies around the time of childbirth could protect children from atopic eczema for up to four years - two years longer than previously reported, say researchers in tomorrow's Lancet.
The allergy atopic eczema is a chronic disease affecting increasing numbers in developed countries. Some experts have attributed this increase to reduced exposure to bacteria during childhood which is thought to prevent the full development of the immune system, although this theory has not been proven.
Marko Kalliomäki and colleagues from Turku University Central Hospital in Finland previously reported results of a randomized trial which showed how consumption of the probiotic Lactobacillus GG (a probiotic which is safe at an early age and effective in the treatment of allergic inflammation and food allergy) halved the incidence of infant atopic eczema at two years of age compared with placebo (see The Lancet 2001; 357: 1076-79).
The same group of investigators will report in tomorrow's issue of journal that children who were exposed to probiotics around the time of birth were 40 per cent less likely to develop atopic eczema at four years of age compared with children in the placebo group. As with the previous study, exposure to probiotics did not have any protective effect over asthma or rhinitis.As in the first study, a group of 159 mothers were randomly allocated to receive two capsules of placebo or probiotics - lactobacillus GG, produced by Finland's Valio - daily for four weeks before expected delivery. After delivery, capsules were taken postnatally for six months (during breastfeeding either the mother or the infant consumed the preparation).
Atopic disease was diagnosed using a questionnaire and a clinical examination. Out of 53 children receiving the probiotics, 14 had developed eczema, compared to 25 in the placebo group (54 in total).
"Our findings show that the preventive effect of Lactobacillus GG on atopic eczema in at-risk children extends to the age of four years. This age, however, does not yet allow the final assessment of any effect on respiratory allergic diseases, since these typically manifest themselves at an older age," said Marko Kalliomäki.The researchers also noted that the immunological effects of probiotic strains vary, even within the same species. "Since the probiotic approach was promising and safe, future studies should focus on detection of new potential successful probiotic strains to be applied in combinations when combating allergic disease," they conclude.