Background: Functional abdominal pain is a very frequent functional gastrointestinal disorder but still without adequate treatment options. Therefore, the main aim of this systematic review and meta-analysis was to evaluate strain-specific probiotic effects on functional abdominal pain in children.

Methods: This was a systematic review and meta-analysis of randomized controlled trials published in a period up to 1st of April 2020 that analyzed probiotic interventions for pediatric functional abdominal pain. We included 9 randomized controlled trials (a total of 702 children, 506 with functional abdominal pain; 4 to 18 years); 8 studies were available for meta-analysis (a total of 641 children). Lactobacillus rhamnosus GG and Lactobacillus reuteri DSM 17938 were the only two probiotic strains investigated.

Results: Significant reduction in pain intensity (6 trials, n = 380, mean difference – 1.24, 95% CI – 2.35 to – 0.13) and increase in number of days without pain (2 trials, n = 101, mean difference 26.42, 95% CI 22.67 to 30.17) were found in children taking L. reuteri DSM 17938. For all other outcomes, there were no significant differences between probiotic and placebo.

Conclusion: Based on the available evidence, no firm conclusions can be given; however, L. reuteri was proven to decrease the pain intensity in children with functional abdominal pain. Further trials regarding long-term outcomes, possibly involving longer interventions, are needed.

What is Known:

• Previously published systematic reviews have suggested that probiotics may have an effect on the pain in children with functional gastrointestinal disorders, but limited data exist on strain-specific effects.

What is New:

• This systematic review provides evidence on the probiotic use on the strain-specific level.
• This systematic review showed that the use of Lactobacillus reuteri DSM 17938 modestly reduces the pain intensity in children with functional abdominal pain.