Probiotic Therapy, What is the most Effective Method for Host Protection Against Enteric Pathogen

Background: prevention of adverse microbial colonization is supposed to be the most important beneficial effect of the gut microflora. objectives: the aims of the present study were to compare the effect of co-incubation, pre-incubation and supernatant of sixteen probiotic strains on prevention of enteroinvasive e. coli adhesion. materials and methods: probiotic strains were added to caco-2 cells followed by e. coli in pre-incubation assay. tested strains and enteroinvasive e. coli were added to cell lines at the same time in co-incubation assay. finally, enteroinvasive e. coli was treated with bacteria free supernatant of test strains then added to cell line in treatment with bacteria free supernatant assay. results: this study showed that the most effective assays in prevention of pathogen adherence were treatment with bacteria free supernatant and pre-incubation respectively. conclusions: the effect of probiotic bacteria by-products on pathogen exclusion may be of more importance in protecting the host. therefore, gut colonization or at least persistent presence of probiotics may be helpful in infection prevention.