Nine RCTs were identified of which eight (n=766) were included in the meta-analyses. Study quality scores ranged from 2 to 5; one RCT scored 2 and was excluded due to poor quality.
The supplemental Lactobacillus regime was associated with more successful eradication (OR 1.78, 95% CI 1.21 to 2.62; eight RCTs) and fewer side effects in terms of diarrhoea (OR 0.23, 95% CI 0.11 to 0.48; five RCTs), bloating (OR 0.41, 95% CI 0.23 to 0.75; three RCTs) and taste disturbance (OR 0.23, 95% CI 0.11 to 0.47; four RCTs) compared to standard Lactobacillus regime. There was no difference between treatment groups when total side effects were considered (six RCTs) and for the individual symptoms of nausea or abdominal pain.
Subgroup analysis showed that eradication rates differed significantly between treatment arms only for symptomatic patients (two RCTs) and clarithromycin plus amoxicillin plus Lactobacillus (five RCTs); differences between treatment groups were not significant for studies conducted in asymptomatic patients (three RCTs), adults (six RCTs) and for clarithromycin plus tinidazole plus Lactobacillus (three RCTs).
The funnel plot showed slight asymmetry, but this was not statistically significant. Significant heterogeneity was noted only for the total side effects analysis.