Mechanisms and actions of prebiotic oligosaccharides and the development of gut microbiota

Background: Accumulating evidence suggests that interaction between intestinal microbiota and gut plays an important role in the postnatal development of the immune system. Non-digestible oligosaccharides in human milk may influence the development of the immune system. The immune modulatory effects of a specific prebiotic oligosaccharide (OS) mixture (90% short chain galacto- and 10% long chain fructo-oligosaccharides; Immunofortis®) was studied in several intervention studies. Method: Several randomised double-blind, placebo-controlled trials have been performed in preterm and term infants to assess the effects of OS on the incidence of atopic dermatitis (AD) and infections. Specific OS mixtures were tested in preclinical models in order to obtain more insight in underlying mechanisms. Results: Supplementation with Immunofortis® reduced the cumulative incidence of AD in high-risk infants. Follow-up data revealed that incidences of AD and infections were still lower in these children later in life. In low-risk infants, the incidence of AD was lower in the group receiving Immunofortis® with acetic oligosaccharides (extended OS mixture) compared to control group. The extended OS mixture reduced serious infectious morbidity in preterm infants. Preclinical studies indicate that these beneficial health effects are mediated by both modulation of intestinal microbiota and direct interactions with immune cells. Conclusions: Oral administration of specific OS appears to be a signifi-cant opportunity to modulate the immune system and might provide an opportunity to prevent infections and allergy. Future research is aimed at the identification of the underlying mechanisms and at further examination of the relationship between early OS supplementation and health effects later in life.