Efficacy of the Probiotic Bifidobacterium infantis 35624 in Functional Abdominal Bloating: A Triple-Blind, Randomized Controlled Trial

Abstract

Background: Functional abdominal bloating (FAB) affects quality of life (QoL), with limited treatment options. Recent studies suggest that the intestinal microbiota plays a role in FAB. This study aimed to assess the efficacy of Bifidobacterium infantis (B. infantis) 35624 in individuals with FAB, according to the Rome IV criteria. Methods: This eight-week, triple-blind, randomized, placebo-controlled trial randomized participants with FAB to receive B. infantis 35624 (1 × 10⁸ CFU) or placebo for four weeks, following a two-week run-in phase with metronidazole. Symptom severity (bloating, postprandial fullness, early satiety, and nausea), frequency (regurgitation, belching, vomiting, flatulence, and defecation), and quality of life (QoL) were assessed at weeks 0, 2, 4, 6, and 8. Holm–Bonferroni correction was applied to outcomes with any unadjusted between-group p-value < 0.05. Results: Sixty-eight subjects (34 probiotics, 34 placebos; 66.2 female, mean age 46.24 ± 11.72) provided evaluable data. Both the probiotic and placebo groups showed significant improvements in bloating, postprandial fullness, belching, nausea, regurgitation, and quality of life (all P < 0.05). The probiotic group also had reductions in early satiety and flatulence, not observed in placebo. No significant between-group differences remained after adjustment. Both regimens were well-tolerated. Conclusion: B. infantis 35624 did not significantly improve bloating, other abdominal symptoms, or QoL compared with placebo in patients with FAB, highlighting the strong placebo effect commonly observed in FGID trials. Further research with longer durations and larger sample sizes is warranted. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.