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VTT BIOTECHNOLOGY
HIGHLIGHT RESULTS: PROPATH
Project Co-ordinator: Prof. Luc De Vuyst ([email protected])
1) The inhibitory activity of bifidobacteria towards Gram-negative, gastrointestinal
pathogens is solely due to the production of organic acids, in particular acetic acid and
lactic acid. Prebiotic inulin-type fructans might modulate the production of organic acids
by lactobacilli and bifidobacteria in the gastrointestinal tract, underlying their potential
activity towards pathogenic bacteria.
2) Lactic acid has an important role in the activity of lactobacilli against Salmonella
Typhimurium. Certain lactobacilli produce heat-stable, non-proteinaceous, specific, antiSalmonella compounds, which are active at low pH and in the presence of lactic acid.
3) Lactobacillus johnsonii La1 produces a bacteriocin, named lactacin Fa, inhibitory to
lactobacilli. The anti-H. pylori activity probably consists of or is depending on a mixture
of low-molecular-mass metabolites and/or protease-sensitive compounds/bacteriocin(s).
4) Lactobacillus johnsonii La1, Lactobacillus casei Shirota, and Lactobacillus amylovorus
DCE 471 significantly decrease H. pylori binding to cultured human gastric
adenocarcinoma AGS cells. Administration of Lb. johnsonii La1 to mice results in a
significant delay of both chronic and chronic-active gastritis.
5) Some lactobacilli such as Lactobacillus johnsonii La1, Lactobacillus casei Shirota, and
Lactobacillus plantarum ACA-DC 287 strongly inhibit the invasion of S. Typhimurium
SL1344 into cultured human enterocyte-like Caco-2 cells. Reduced S. Typhimurium levels
are observed in the gastrointestinal tract and tissues of Salmonella-infected mice after
administration of cultures of Lb. casei Shirota and Lb. fermentum ACA-DC 179.