Previous studies using dietary intervention with scGOS/lcFOS-containing NDO mixtures [24,31,32], as well as human milk oligosaccharide 2′-fucosyllactose (2′FL) [38] and the combination thereof [47], have shown similar effects on Th1-dependent responses to an influenza vaccine, and increased proliferation of vaccine-specific CD4+ and CD8+ T cells and higher production of IFN-γ after ex-vivo re-stimulation of splenocytes in vaccinated mice [38]. Here, CD4 is linked to influenza.