Comparative effects of six probiotic strains on immune function in vitro

Area of Science:

• Immunology
• Microbiology
• Gastroenterology

Background:

• Probiotics modulate the immune system, but strain-specific effects require further investigation.
• Understanding immune responses to specific probiotic strains is crucial for targeted therapeutic applications.

Purpose of the Study:

• To compare the immunomodulatory effects of six different probiotic strains (four Lactobacillus and two Bifidobacterium species) in vitro.
• To investigate strain-specific differences in immune cell activation and cytokine production.

Main Methods:

• Human peripheral blood mononuclear cells (PBMCs) were incubated with live probiotic cells for 24 hours.
• Flow cytometry was used to assess activation markers (CD69, CD25) on lymphocytes, T cells, and NK cells.
• Cytokine production (IL-1β, IL-6, IL-10, TNF-α, etc.) was measured using ELISA and multiplex assays.

Main Results:

• All tested probiotic strains increased CD69 and CD25 expression on immune cells and enhanced natural killer (NK) cell activity.
• Cytokine production varied among strains, with significant differences observed for IL-10, IFN-γ, TNF-α, IL-12p70, IL-6, and MCP-1.
• Lactobacillus strains tended to promote T helper 1 cytokines, while Bifidobacterium strains exhibited a more anti-inflammatory profile.

Conclusions:

• Limited strain-specific effects were observed for T cell and NK cell activation and NK cell activity.
• Probiotic strain selection can influence cytokine profiles, suggesting potential for targeted immunomodulation.
• Further research is needed to elucidate the full spectrum of strain-specific immune modulation by probiotics.