Immunomodulatory influences of sialylated lactuloses in mice

The aim of this study was to investigate the immune modulatory influences of sialylated lactuloses in mice. The effects of the four sialylated lactuloses by gavage methods on the weight gain rate, organ, serum and spleen immunoglobulin of mice were investigated. Neu5Ac-alpha 2,3-lactulose group and Kdn-alpha 2,3-lactulose group had significantly higher weight gain rate than control group. The weight gain rate, thymus index and spleen index of Kdn-alpha 2,3-lactulose group were significantly higher than control group and lactulose group. Liver and small intestine of Neu5Ac-alpha 2,3-lactulose group, Neu5Ac-alpha 2,6-lactulose group and Kdn-alpha 2,6-lactulose group showed different degree of damage. IgG levels of serum and spleen in Neu5Ac-alpha 2,6-lactulose group and Kdn-alpha 2,6-lactulose group were significantly higher than control group and lactulose group. The contents of IgG in serum and spleen of Kdn-alpha 2,3-lactulose group were significantly lower than that of control group, while the contents of IgA and IgM in serum were significantly higher than those of control group. The IgA level increased by 12.23% and 58.77% comparing with lactulose group and control group, respectively. The IgM level in serum of Kdn-alpha 2,3-lactulose group mice increased by 43.88% and 8.05% comparing with control group and lactulose group, respectively. The IgA level and IgM level in spleen of Kdn-alpha 2,3-lactulose group mice increased by 49.05% and 47.25% comparing with control group. In short, Kdn-alpha 2,3-lactulose is relatively safe and superior to use as a food supplement or potential drug candidate. Our results also indicate that some other sialylated oligosaccharides are potentially harmful to organisms, they may cause some side effects. (C) 2019 Elsevier Inc. All rights reserved.