Bifidobacteria are the predominant components of the intestinal flora in breast-fed infants.
Growing research has revealed that breast milk provides a continuous supply of probiotic
bacteria to the infants’ gastrointestinal tract. These bacterial groups play a vital role in
maintaining the gut health. Furthermore, they could also protect the infants from pathogen
infections and contribute to the development and maturation of the systemic immunity. In
this study, in addition to conventional probiotic screening criteria, eighteen Bifidobacterium
strains isolated from breast milk were screened for their ability to induce cytokine production
of human peripheral blood mononuclear cells with an attempt to select the potentially
immunomodulatory strains. The results indicated that not only different species but also
different strains have different effects on stimulation of cytokine production. Among all
the probiotics isolated from human breast milk, Bifidobacterium adolescentis DB-2458 and
Bifidobacterium longum subsp. infantis GB-1496 exhibited stronger immunomodulatory ability
in comparison with other strains as evidenced by higher Th1-associated cytokine induction
and lower Th2-associated cytokines production, the action which switches the
immune response from Th2 toward Th1 polarization. Therefore, the two Bifidobacterium
strains have great potential for development of functional foods, especially for infants’
nutritional supplements.