Digestery
Everyday supplements › Probiotics and the Gut › Studies

Pooled review (meta-analysis)

Pooled review of 54 trials in irritable bowel syndrome: probiotics improved symptoms

Wu and colleagues · Nutrients · 2024

Original title: The Efficacy of Probiotics, Prebiotics, Synbiotics, and Fecal Microbiota Transplantation in Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Points to benefit

Probiotics improved IBS symptoms (OR = 0.53, 95% CI, 0.48 to 0.59), mainly Bifidobacterium and Lactobacillus strains. No serious side effects were reported. The best strain or mix remains unclear.

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
54 studies · adults with IBS
What was tested
Probiotics (54 trials), compared with placebo; Bifidobacterium and Lactobacillus strains did best. Prebiotics, synbiotics and stool transplants were also compared.
What it measured
The question itself: gut symptoms such as bloating, pain and irregular bowels
Who has a stake
No stake declared
No competing interests declared.
Journal
Nutrients, 2024
Source
PubMed record 38999862. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 54 studies.
  • •A pooled review is only as strong as the studies it pools.
  • ✓Measured the question itself: gut symptoms such as bloating, pain and irregular bowels.
  • ✓No competing interests declared.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: gut symptoms such as bloating and IBS

    9

    5 benefit, 2 mixed, 2 no difference

  2. Trials in people: other measures

    10

    4 benefit, 2 mixed, 4 no difference

  3. Trials in people: lab tests or safety

    0

    None among the papers we read.

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Do probiotics improve gut health?”

Some strains may help some symptoms.

Confidence: low. Based on 28 on-topic papers.

Read the full answer
  • Summed up in “What reviews found”: Pooled 54 probiotic trials in adults with IBS. Probiotics improved symptoms (OR = 0.53, 95% CI, 0.48 to 0.59), mainly Bifidobacterium and Lactobacillus strains, with no serious side effects. The best strain or mix remains unclear.
  • Open item for a person: IBS reviews Goodoory 2023, Wu 2024 and Zhang 2022 likely pool many of the same trials; Chen 2025 pools earlier meta-analyses.

Other reviews on this question

See all 28 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
Not yet. Required before search engines may list this page.

Spot an error? Email a flag with a link to your source, or use the form on the question page.