engleski

Functional properties of probiotic strain Lactobacillus acidophilus M92

Lactobacillus acidophilus M92 was previously selected as probiotic strain on the base of in vitro selection criteria. To investigate functional properties of this strain in vivo, Swiss albino mice were used as animal model. Survival, competition, adhesion and colonization were monitored in the gastrointestinal tract, as well as immunomodulating capability of L. acidophilus M92. During the feeding of mice with probiotic strain with daily dose of 2 x 1010 rifampicin-resistant cells, the number of lactic acid bacteria in faeces was increased and reduction of enterobacteria and sulphite-reducing clostridia was observed. Rifampicin-resistant colonies of L. acidophilus M92 could be reisolated from the faeces of mice fed with the rifampicin-resistant cells. The similar results were obtained in homogenates of small and large intestine of mice in the 1st and 14th day after feeding with L. acidophilus M92. Rifampicin-resistant colonies were identified as L. acidophilus M92 by pulsed-field gel electrophoresis (PFGE). The adherence of examined probiotic strain obtained in vitro correlated with its capability to adhere to mouse ileal epithelial cells in vivo. SDS-PAGE of cell surface proteins revealed the presence of surface layer proteins (S-layer). By in vitro adhesion test it was demonstrated that these S-layer proteins are responsible for adhesiveness of L. acidophilus M92 to mouse ileal epithelial cells. Increase of total antibodies titer (IgA, IgG and IgM) after immunization of mice with viable cells of L. acidophilus M92, confirms immunomodulating property of this probiotic strain.

probiotics; Lactobacillus acidophilus; adhesion; immunomodulation; PFGE; S-layer proteins

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