suppressive effect of lactobacillus acidophilus on antibiotic resistant h.pylori strains isolated from gastric patients

objective: current of antibiotic treatment for h.pylori infection is often associated with frequent adverse effect and resistant to antibiotic. alternative treatment method to control h.pylori infection is needed. the aim of this study was to test in vitro anti helicobacter activity of lactobacilli acidophilus isolated from yogurt. material and methods: forty h.pylori strains isolated from 145 human gastric biopsies. after the primary culture of biopsies in the brucella blood agar and identification of h.pylori by biochemical tests, susceptibility tests to antibiotics (metronidazole, clarithromycin, amoxicillin and tetracycline) were performed with mddm (modified disk diffusion method) and e test. the isolates were cultured in brucella broth and the effect of lactobacillus acidophilus isolated from yogurt (cultured in mrs broth) on growth of h.pylori was tested by a mixed culture technique (co-culture). results: twenty five (62.5%) of the 40 h.pylori isolates were resistant to antibiotics. resistance rates to metronidazole, clarithromycin, amoxicillin and tetracycline were 62.5%, 22.5%, 2.5% and 0% respectively. twenty two (56%) of the 40 h.pylori isolates were inhibited by l. acidophilus in mixed culture. this inhibition occurred only when the two organisms were incubated together for more than 24 h. lactobacillus acidophilus was able to inhibit the growth of both antibiotic sensitive and resistant h.pylori strains. fifteen (68.2%) of the inhibited isolates were susceptible to antibiotics and seven (31.8%) were resistant to antibiotics. conclusion: we observed a significant suppression in the growth of h.pylori in the presence of l. acidophilus. this occurred only when the two organisms were incubated together for more than 24h. based on our findings, l. acidophilus was found to be a potentially effective probiotics against h.pylori and could enhance antibiotic therapy for h.pylori eradication in humans.