Iğdır Üniversitesi Fen Bilimleri Enstitüsü Dergisi, cilt.16, sa.2, ss.566-573, 2026 (TRDizin)
Since the drug-resistant strains, prolonging treatment duration, increasing mortality rates, together with raising healthcare costs caused by antibiotic resistance has become a critical global problem, the scientists have been seeking alternative treatments options such as probiotic supplementation. The present study aimed to investigate the antimicrobial effects of standard probiotic microorganisms (Lactiplantibacillus plantarum ATCC 14917, Lactobacillus fermentum ATCC 14931, Bifidobacterium bifidum ATCC 29521 and Bifidobacterium longum 15707) isolated from various probiotic homemade and commercial probiotic products and pharmacy preparations on standard and clinical strains of Pseudomonas aeruginosa and Escherichia coli. The antimicrobial activity of the probiotic microorganisms on the pathogenic microorganisms was assessed by spot on lawn method. Among the tested probiotics, Lactiplantibacillus plantarum, Lactobacillus kefirii, Bifidobacterium spp. L. plantarum ATCC 14917, L. fermentum ATCC 14931, B. bifidum ATCC 29521 and B. longum ATCC 15707 showed activity against all P. aeruginosa and E. coli strains. However, Enterococcus faecium and B. bifidum ATCC 29521 isolated from pharmacy preparation were effective only against E. coli and had no effect on P. aeruginosa. Furthermore, the results of present study could shed light on the future studies in this area.