The Ameliorating Effect of Lactobacillus gasseri OLL2716 on Functional Dyspepsia in Helicobacter pylori-Uninfected Individuals: A Randomized Controlled Study

<b><i>Background/Aims:</i></b> Probiotics appear to improve <i>Helicobacter pylori</i>-associated dyspepsia via an inhibitory effect on <i>H. pylori;</i> however, uncertainty exists regarding their effects in <i>H. pylori</i>-uninfected individuals. We evaluated the efficacy of <i>Lactobacillus gasseri</i> OLL2716 (<i>L. gasseri</i> OLL2716) on <i>H. pylori</i>-uninfected individuals with functional dyspepsia (FD). <b><i>Methods:</i></b> A double-blind, parallel-group, placebo-controlled, randomized, controlled trial was performed. Participants were randomly assigned to ingest <i>L. gasseri</i> OLL2716-containing yogurt (<i>L. gasseri</i> OLL2716 group) or <i>L. gasseri</i> OLL2716-free yogurt (placebo group) for 12 weeks. Participants completed questionnaires that dealt with a global assessment as well as symptom severity. The per-protocol (PP) population was evaluated for efficacy in accordance with a plan prepared beforehand. <b><i>Results:</i></b> Randomization was performed on 116 individuals; the PP population consisted of 106 individuals (mean age 42.8 ± 9.0). The impressions regarding the overall effect on gastric symptoms were more positive in the <i>L. gasseri</i> OLL2716 group compared to that in the placebo group (statistical trend; <i>p</i> = 0.073). The elimination rate for major FD symptoms was 17.3 and 35.3% in the placebo and <i>L. gasseri</i> OLL2716 groups respectively (<i>p</i> = 0.048). <b><i>Conclusion:</i></b><i>L. gasseri</i> OLL2716 has beneficial effects on FD without <i>H. pylori</i> involvement.