In vitro investigations of the effect of probiotics and prebiotics on selected human intestinal pathogens

Abstract

This study investigated the effects of selected probiotic microorganisms, in combination with prebiotics, on certain human intestinal foodborne pathogens. Probiotics grown with different carbohydrate sources were observed to inhibit growth of Escherichia coli, Campylobacter jejuni and Salmonella enteritidis, with the extent of inhibition varying according to the carbohydrate source provided. Prebiotics identified as being preferentially utilised by the probiotics tested were oligofructose (FOS), inulin, xylo-oligosaccharide (XOS), and mixtures of inulin:FOS (80:20 w/w) and FOS:XOS (50:50 w/w). Two of the probiotics, Lactobacillus plantarum and Bifidobacterium bifidum were selected for further co-culture experiments. Each was combined with the selected prebiotics, and was observed to inhibit pathogen growth strongly. Results suggested that acetate and lactate were directly conferring antagonistic action, which was not necessarily related to a lowering of culture pH. ß

Production and physicochemical characterization of acidocin D20079, a bacteriocin produced by Lactobacillus acidophilus DSM 20079

“…Bacteriocin production has been shown for a number of such strains (Kawai et al 2000), and is often proposed as a beneficial characteristic of probiotic bacteria (Klaenhammer and Kullen 1999;Fooks and Gibson 2002). Lately intense investigation on bacteriocins from LAB, has led to considerable progress toward a better understanding of these substances.…”

Application of inulin in cheese as prebiotic, fat replacer and texturizer: A review

“…FOS changes the intestinal metabolic balance toward carbohydrate versus protein fermentation, reducing the generation of harmful by-products like phenols (Birkett and Francis, 2010). Lactobacillus plantarum 0407 and Lactobacillus pentosus 905 combined with FOS, inulin, XOS and mixtures of inulin:FOS and FOS:XOS are effective in inhibiting the growth of Escherichia coli and Salmonella enterica serovarEnteritidis(Fooks & Gibson, 2002). Preventive effects of FOS have been also revealed against the growth and activity of pathogens, such as Salmonella typhimurium and Clostridium difficile(Birkett and Francis, 2010).FOS, inulin, XOS and their mixtures, have all been reported to cause greater inhibition than lactulose, lactitol, starch and dextran, perhaps suggesting a structure-to-function relationship in terms of the prebiotic used.…”

Probiotics and Prebiotics

“…␤-galactosidase) r Production of antibacterial substances inhibiting the pathogen's growth r Protective effect on and rebuilding of microflora after such gastrointestinal disorders as infection-related diarrhea (traveler's diarrhea, acute viral diarrhea in children), antibioticassociated diarrhea and radiotherapy-associated diarrhea r Reduction of cholesterol levels r Stimulation of the immune system r Increased colon peristalsis and prevention of constipation r Reduction of adherence and colonization by pathogens r Anti-allergenic activity r Reduction of activity of fecal enzymes responsible for the transformation of procarcinogens into carcinogens (protection against colon cancer) r Maintenance of continuity of intestinal mucosa Most of the above-mentioned probiotic properties result from the activity of metabolites produced by probiotic bacteria. In this respect several examples may be presented, such as bacteriocins responsible for the elimination of pathogenic bacteria, peptides for reduction of blood pressure, proteolytic enzymes for the elimination of food allergies, ␤-galactosidase for lactose digestion, cholesterol oxidase for the reduction of cholesterol, linolic acid conjugates for increasing antioxidant potential, enzymes for eliminating carcinogens and adhesins on the surface of bacterial cells acting as immunostimulants (Fooks & Gibson 2002;Saxelin et al 2005;Shah 2007).…”

“…Strong adhesion to the intestinal epithelium extends the time during which a given strain remains in the alimentary tract and offers a better chance for humans to be protected against contact with pathogens. A long-lasting colonization of the alimentary tract by probiotic microorganisms is also promoted by their resistance to bacteriocins, acids and other antagonistic compounds produced by the endogenous microflora colonizing the intestinal ecosystem (Fooks & Gibson 2002).…”