Metabolic and functional properties of lactic acid bacteria in the gastro-intestinal ecosystem: A comparative in vitro study between bacteria of intestinal and fermented food origin

Metabolic and functional properties of probiotic lactic acid bacteria (LAB) in the human gastro-intestinal ecosystem may be related to certain benefic ial health effects. In this study, lactobacilli of either intestinal or fer mented food origin were compared in their capability to survive low pH and bile, in their metabolic activity in the presence of bile salts and mucins, as well as in their potential to attach to enterocyte-like CaCO-2 cells. F ood fermenting bacteria especially strains of the species Lactobacillus pla ntarum showed high tolerance to the consecutive exposure to hydrochloric ac id (pH 1.5-2.5) and cholic acid (10 mM). Growth in and deconjugation of gly cocholic (5 mM) and taurocholic acids (5 mM), as demonstrated for all lacto bacilli of intestinal origin, was detected for food fermenting strains of t he species L. plantarum, but not L. paracasei and L. sakei. Degradation of mucins was not observed for lactobacilli. Adhesion to the intestinal epithe lial cell line CaCO-2 was demonstrated for several food fermenting bacteria l strains in vitro. Soluble factors in the spent culture supernatants from intestinal and fermented food lactobacilli but not staphylococci cross reac ted and synergized with cell wall components to promote adhesion to CaCO-2 cells. A competitive role of fecal bacteria on the adhesion of lactobacilli to CaCO-2 cells was demonstrated. In conclusion we have shown that metabol ic and functional properties of intestinal lactobacilli are also found in c ertain bacteria of fermented food origin.