Significant reduction in allergy symptoms in the offspring of mice supplemented with specific nondigestible oligosaccharides during pregnancy

Background: Previous studies from our laboratory indicate that maternal supplementation with non-digestible carbohydrates may beneficially affect maternal and fetal immune status in mice. We therefore chose to investigate whether maternal supplementation during pregnancy could have long-term effects on the immune response in the offspring of both sensitized and nonsensitized dams. To this end, we studied immune responses in the offspring in an ovalbumin (OVA)-induced model for experimental allergic asthma. Method: Female mice were sensitized twice via i.p. injection to ovalbumin (OVA) or PBS as a control. Two weeks after the last sensitization, mice were transferred to either a control diet or a diet supplemented with short-chain galacto- and long-chain fructo-oligosaccharides (scGOS/lcFOS; ratio 9:1). Two weeks later, mice were mated. Directly after birth of the offspring, all mice were again transferred to the control diet. The male offspring were sensitized to OVA at the age of six weeks, and the acute allergic skin response was measured at the age of 8 weeks. The offspring were subsequently challenged three times with nebulized OVA, after which airway hyperreactivity to metacholin was measured. Hereafter the offspring were sacrificed and ex-vivo parameters were measured. Result: In offspring of non-sensitized dams supplemented with scGOS/lcFOS a reduction in the acute allergic skin response could be observed as compared to the offspring of non-sensitized dams fed the control diet. This effect was not observed in offspring of sensitized dams. Correspondingly, a dramatic decrease in lungresistance as a response to metacholine challenge was seen in offspring of non-sensitized dams supplemented with scGOS/lcFOS. Furthermore, whereas IgE levels were elevated in the offspring of non-sensitized dams fed the control diet, no such increase was observed for the offspring of non-sensitized dams supplemented with scGOS/lcFOS. IgG2a levels were significantly higher in the latter group compared to the other experimental groups, and a significant increase in the percentage of regulatory T cells in the spleen was observed. Conclusion: Maternal supplementation with scGOS/lcFOS during pregnancy leads to a significant decrease in allergic symptoms in the offspring of non-sensitized mice. Underlying mechanisms need to be further examined but the data from this study suggest a role for regulatory T cells.