Different biological control agents are used to fight various pathogens or even harmful organisms in different environments. Among these agents, a wide range of bacteria belonging to the genus Bifidobacterium spp are capable to produce a large number of enzyme and secondary metabolites with the properties of antibacterial activity. The main aim of the present work was the evaluation of the antagonistic activity of Bifidobacterium spp against pathogenic bacteria Helicobacter pylori, which was responsible for ulcer gastric disease by the using of agar well diffusion method and the study of the bacterial growth in the absence and in the presence of the supernatant of Bifidobacterium spp. The obtained results showed that the tested antagonistic activity of Bifidobacterium spp against Helicobacter pylori has manifested an excellent antibacterial activity with a maximal diameters of inhibition zone over 15 mm respectively. Furthermore, the study of bacterial growth of Helicobacter pylori in the absence and in the presence of the supernatant of Bifidobacterium spp indicated a considerable biomass reduction accompanied with unbalanced growth after adding of the supernatant.
