Background and Aim: To evaluate the effect of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus to Helicobacter pylori eradication in different periods of therapeutic protocol.

Methods:  Infected patientswere randomized to one-week tailored triple therapy (esomeprazole 20mg bid, clarithromycin 500mg bid/metronidazole 400mg tid if clarithromycin resistant, and amoxicillin 1000mg bid) with placebo (group 1, n = 100); one week of pretreatment with probiotics (group 2, n = 100); and one week of pretreatment with probiotic followed by one week of the same probiotics after treatment (group 3, n = 100).

Result:  PP analysis involved 292 patients, 98 in group 1, 97 in group 2, and 97 in group 3. Successful eradication was observed in 229 patients; by PP analysis, the eradication rates were significantly higher (P < 0.01, 95% CI; 0.71–0.97) in group 2 and group 3 than group 1.

ITT analysis eradication rates were significantly higher in group 2 and group 3 than group 1 (P < 0.01 95% CI; 0.72–0.87), and there is no significant difference between the three groups (P = 0.32) in terms of adverse events.

Conclusion: Adding probiotics before or before and after tailored treatment can improve Helicobacter pylori eradication rates.