CD40LG and influenza: Regarding influenza vaccination, the hypothesis that the main immune cell type involved is T cells is supported by the results obtained in Bunout et al.’s clinical study, showing no influence of fructooligosaccharide consumption by healthy elderly on immunoglobulin levels (IgA, IgM, IgG and salivary secretory IgA) after influenza vaccine [58], which is consistent with Udani’s results on arabinogalactan [32].