Several studies on the pathogenesis of allergy both in man and experimental animals continue to show the importance of commensal bacteria in the gastrointestinal tract in stimulating and directing the immune system. The interest in modulating commensal bacteria flora with pre- and probiotics to prevent and treat food allergy has multiplied in recent years. We recently studied 230 infants with atopic dermatitis and suspected cow’s milk allergy. The infants were randomly allocated to groups which received Lactobacillus GG (LGG), a mixture of four probiotic strains (MIX) or placebo for 4 weeks. We inferred that probiotics induce systemically detectable low-grade inflammation, which may explain the clinical effects and the secretion pattern of cytokines induced by PBMC. To study the ability of probiotics to prevent allergy in children, we recruited 1223 pregnant women carrying fetuses at increased risk of allergy for a double-blind placebo-controlled trial. Mothers used a mixture of four probiotic bacteria or a placebo from the 36th week of gestation. Their infants received the same probiotics plus prebiotic galacto-oligosaccharides for 6 months. At the 2-year follow-up, a total of 925 infants participated. The cumulative incidence of allergic disease did not differ significantly between the synbiotic and the placebo group. However, synbiotics significantly reduced eczema. The preventive effect of synbiotics was more pronouncedagainst IgE-associated diseases. At the 5 year follow-up, 891(88%) of the 1018intention-to-treat infants attended. In the probiotic and placebo groups, frequencies ofallergic symptoms and IgE-associated allergic disease and sensitization were similar, andthe frequencies of eczema did not differ between the groups. Atopic eczema, allergicrhinitis and asthma appeared equal frequency in the groups. However, less IgE-associatedallergic disease occurred in the cesarean-delivered infants given probiotics. Incesarean-delivered childen, we noticed a delayed rise in bifidobacteria recovery inplacebo-treated children which was corrected by pro- and prebiotic supplementation.Indications from studies of feces and blood at the age 6 months suggest that probioticsmay enhance both inflammation and immune defence of the gut. The probiotic treatmentfurther stimulated maturation of the immune system since the infants given probioticsshowed increased resistance to respiratory infections and improved vaccine antibodyresponses.
展开▼
