Potential of probiotic strains to modulate the inflammatory responses of epithelial and immune cells in vitro.

Lactobacilli are important human commensal microbiota that are considered to be probiotic as they have been shown to reduce pathogenic infections and chronic inflammation. This study compared 4 strains of lactobacilli for their probiotic potential. These 4 strains showed varying capacities for adhesion and cytokine induction (interleukin [IL]-8 and IL-10) in different human epithelial cells, such as primary cultures of buccal cavity cells, and established cell lines derived from epithelia of the pharynx, intestine and cervix. After exposure to lactobacilli, secretion of cytokines (IL- 10, IL-12p70, interferon-?, and tumor necrosis factor-?) was induced at varying levels in different cultures of human immune cells, including dendritic cells, monocyte-depleted peripheral blood mononuclear cells, CD14+ cells, CD4+CD25- T cells, and regulatory T-cells. Growth inhibition of pathogenic strains was detectable in the presence of lactobacilli in vitro. Moreover, among the 4 strains tested, Lactobacillus salivarius sp. salicinius AP-32 was found to have the highest probiotic potential. This study highlights the complex host-pathogen-microbiota interactions and indicates that a combination of strains may have to be used to provide all the desirable probiotic benefits.

Fermentation of banana media by using kappa-carrageenan immobilized Lactobacillus acidophilus.

Fermentation media were prepared by using banana as the raw material, and cell immobilization of Lactobacillus acidophilus by kappa-carrageenan entrapment was applied to enhance the fermentation efficiency. Gel beads of diameters around 3.0 mm were prepared for the immobilized cells, ripe bananas were used for preparation of media, and both free and immobilized cells were employed to carry out the fermentation for 80 h. Cells leaked out from the gel beads and proliferated in the medium solution during the fermentation of immobilized cells. The final viable cell number reached 10(5) CFU/ml in the medium suspension, over 10(8) CFU/(ml gel) in gel beads for the immobilized cell fermentation and around 10(6) CFU/ml for the free cell fermentation. Immobilized cells withstand the adverse conditions in banana media resulting in better fermentation efficiency compared to free cells. Variation of fructooligosaccharides (FOS) in banana media was not significant in immobilized cell fermentation compared to free cell. Immobilized L. acidophilus fermented banana medium was found to possess synbiotic properties.