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Open AccessVollständige AnalyseJun 16, 2026

Multi-species synbiotic vs. placebo for bloating, gas, and abdominal discomfort: a 6-week randomized controlled trial

Six weeks of multi-species synbiotic supplementation (24 strains + pomegranate extract) significantly improved digestive quality of life, bloating/gas, and abdominal pain scores versus placebo in generally healthy adults with chronic complaints.

The question (PICO)
PopulationGenerally healthy U.S. adults with self-reported bloating/indigestion for ≥3 months, no medical GI diagnosis (n=350 at baseline; n=219 with complete data at week 6)
InterventionMulti-species synbiotic: 53.6 billion AFU (24 Bifidobacterium and Lactobacillus strains) + 400 mg Indian pomegranate extract (>40% polyphenols), 2 capsules/day for 6 weeks
VergleichPlacebo (rice flour), identical administration for 6 weeks
EndpunktPrimary: digestive quality of life (DQLQ, week 6). Secondary: bloating/gas (NIH PROMIS-GI 13a), abdominal pain/discomfort (NIH PROMIS-GI 5a), constipation, anxiety, safety
BEvidenz
Studie
Randomized controlled trial
Stichprobe
219
Effekt
Günstig
Dauer
6 Wochen
Zusammenfassung der Ergebnisse nach Endpunkt
EndpunktGradRichtungEffektStudien
Digestive quality of life (DQLQ)B Günstigp<0.05 vs placebo; IC 95% NR1
Bloating and gas (PROMIS-GI 13a)B Günstigp<0.05 vs placebo; IC 95% NR1
Abdominal pain/discomfort (PROMIS-GI 5a)B Günstigp<0.05 vs placebo; IC 95% NR1
ConstipationC GünstigLikert 5-pt; IC 95% NR1
Anxiety (PROMIS-Anxiety 4a)C UnzureichendIC 95% NR; direção não confirmada no extrato1
Safety (adverse events)B NeutralSem eventos adversos graves atribuídos; IC 95% NR1
Digestive quality of life (DQLQ)B
Richtung Günstig
Effektp<0.05 vs placebo; IC 95% NR
Studien1
Bloating and gas (PROMIS-GI 13a)B
Richtung Günstig
Effektp<0.05 vs placebo; IC 95% NR
Studien1
Abdominal pain/discomfort (PROMIS-GI 5a)B
Richtung Günstig
Effektp<0.05 vs placebo; IC 95% NR
Studien1
ConstipationC
Richtung Günstig
EffektLikert 5-pt; IC 95% NR
Studien1
Anxiety (PROMIS-Anxiety 4a)C
Richtung Unzureichend
EffektIC 95% NR; direção não confirmada no extrato
Studien1
Safety (adverse events)B
Richtung Neutral
EffektSem eventos adversos graves atribuídos; IC 95% NR
Studien1

Kontext

Bloating affects approximately 1 in 7 Americans weekly and impairs quality of life. Prior single- or dual-strain probiotic trials in healthy individuals failed to show benefit for bloating and gas. This trial tests whether a 24-strain synbiotic with polyphenolic prebiotic changes that outcome.

Was die Studie zeigte

The synbiotic group showed statistically significant improvement in DQLQ score (digestive quality of life) versus placebo at week 6 (direction: favors synbiotic; absolute values and 95% CI not explicitly reported in available text). PROMIS-GI bloating/gas and abdominal pain/discomfort scores also improved significantly in the active versus placebo group. No serious adverse events were attributed to the synbiotic. Effect sizes were expressed as score differences on validated instruments, not as absolute event counts.

Wie es durchgeführt wurde

Randomized, double-blind, placebo-controlled, parallel-group, decentralized (online) trial conducted in the USA over 6 weeks. Participants recruited via social media and email lists; 1:1 randomization. Of 622 screened, 350 enrolled at baseline and 219 completed week-6 assessment (~37% attrition).

Effektgröße

Specific effect sizes (SMD, MD, RR, OR with 95% CI) were not extractable from the available full text; authors report statistical significance (p<0.05) for primary and key secondary endpoints, with the trial powered at 90% for n=210 evaluable participants.

Einschränkungen

~37% attrition (350→219) with potential unadjusted attrition bias; intention-to-treat analysis not confirmed in the available extract. Online self-selected recruitment limits representativeness. No objective measures (e.g., hydrogen breath test, manometry). Six-week duration precludes conclusions on durability of effects. Potential conflict of interest: product is marketed by Seed Health, Inc. RoB 2 tool not applied by authors.

In der klinischen Praxis

In generally healthy adults with chronic bloating and no medical diagnosis, this 24-strain synbiotic with polyphenolic prebiotic showed reduced bloating, gas, and abdominal discomfort scores over 6 weeks. Clinicians should weigh the incompletely quantified effect size against cost, high study attrition, and potential sponsor conflict of interest. This study provides no basis for recommending the product in IBS or other diagnosed GI conditions.

Was noch fehlt

Trials with ≥6-month follow-up, rigorous intention-to-treat analysis, objective measures of intestinal fermentation, and independent (non-industry-funded) replication are needed to consolidate the evidence.

Quelle: DOI 10.3390/nu18020255 · 2026

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