• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.584-589
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• 2006

Bifidobacteria has been suggested to exert health promoting effects on the host by maintaining microbial flora and modulating immune functions in the human intestine. We assessed modulatory effects of the different cell fractions of Bifidobacterium sp. BGN4 on macrophage cells and other immune cells from the spleen and Peyer's patches (PP) of mouse. Cell free extracts (CFE) of the BGN4 fractions induced well-developed morphological changes in the macrophages and increased the phagocytic activity more effectively than other fractions in the mouse peritoneal cells. Nitric oxide (NO) production was significantly reduced by both the cell walls (CW) and CFE in the cultured cells from the spleen and PP. The production of interleukin-6 (IL-6) and interleukin-10 (IL-10) was eminent in the spleen cells treated with experimental BGN4 cell fractions. However, in the PP cells, IL-6 was slightly decreased by the treatment with the whole cell (WC) and CW, whereas IL-10 was significantly increased by the treatment with the CW and CFE. These results suggest that different types of bifidobacterial cell fractions may have differential immunomodulatory activities depending on their location within the host immune system.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.81-84
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• 2005

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.276-281
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• 2003

The adhesion of probiotic bacteria to the intestinal mucosa is one of the desirable properties for their colonization in the intestinal tract, where these bacteria constantly compete with other bacteria. The adhesion of different strains of bifidobacteria to Caco-2 cells was compared. Among the strains examined, BGN-4 showed the highest adhesion level and the greatest cell surface hydrophobicity (CSH). No close relationship was found between the adhesion and CSH of the strains. Upon protease and heat treatment, the adhesion of the BGN-4 to the Caco-2 cells decreased significantly. The cells grown at $42^{\circ}C$ showed a lower CSH and self-aggregation levels than cells grown at $37^{\circ}C$. The treatment of EGTA did not have any effect on the adhesion. The degree of adhesion did not differ among the experimental groups in which galactose, mannose, or fucose were added in the adhesion assay mixture. The results suggest that the adhesion of the Bifidobacterium to the epithelial cells may be affected by the composition and structure of the cell membrane and interacting surfaces.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.740-744
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• 2005

Bifidobacterium has been previously shown to potentiate immune function, which was mediated through the stimulation of cytokine production by macrophage. This study was performed to further characterize the effective component of Bifidobacterium by measuring the level of interleukin (IL)-6 cytokine using the RAW 264.7 murine cell line as a macrophage model. RAW 264.7 cells were cultured for 24 h in the presence of whole cells (WCs), cell walls (CWs), and cell-free extracts (CFEs) from various strains of Bifidobacterium and other lactic acid bacteria at various concentrations. The most effective component was different depending on the strains and the concentrations used. When tested with each cell fraction from Bifidobacterium sp. BGN4, heat treatment of the cell fractions lowered the production of IL-6. Synergistic effect was obtained, especially when CWs and CFEs were combined. Sonicated WCs stimulated IL-6 production more than intact WCs. The in vitro approaches employed here should be useful in further characterization of the effects of Bifidobacterium on gastrointestinal and systemic immunity.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.142-142
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• 2004