Searching for the Perfect Homeostasis: Five Strains of Bifidobacterium longum From Centenarians Have a Similar Behavior in the Production of Cytokines

GOALS: To investigate the modulation of human cytokines by Bifidobacterium longum strains isolated from Centenarians. In particular, we measured the production of interleukin (IL)-12p70, interferon-γ, IL-17A, and IL-4 from human peripheral blood mononuclear cells after stimulation with live bacteria. BACKGROUND: Probiotics may inhibit pathogens and modulate the immune system, bringing a beneficial effect on human health. Among the probiotic strains, bifidobacteria play a key role in the maturation of the host's immune system. At present, only a few comparative data are available on the effects of bifidobacteria associations on cytokine production. STUDY: Peripheral blood mononuclear cells were isolated, cultured, and stimulated (ratio 1:1) with B. longum DLBL07, B. longum DLBL08, B. longum DLBL09, B. longum DLBL10, or B. longum DLBL11, either alone or in association. Cytokine production was determined by an enzyme-linked immunosorbent assay. RESULTS: Both the B. longum DLBL mixture and the individual B. longum DLBL strains induced similar levels of IL-4, interferon-γ, and IL-17A. Under all conditions tested, no IL-12p70 release was detected. CONCLUSIONS: The fact that B. longum strains were obtained from Centenarians suggests a perfect homeostasis between this specific species and the host. Moreover all the B. longum strains from Centenarians used in our study share some biological similarities.