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Randomized trial · measured other health measures

8-week trial in 75 adults with depression: no clear gut or mood change

Söderberg Veibäck and colleagues · Brain, behavior, and immunity · 2025

Original title: Add-on probiotics for inflammatory depression - A double-blind randomized placebo-controlled trial.

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

No difference

No effect of the probiotic vs placebo on depression scores or on other measures, including gut symptoms (all p > 0.25).

The study at a glance

Type of study
Randomized trial
Who or what was studied
75 people · 75 overweight adults with depression and signs of body inflammation
What was tested
Limosilactobacillus reuteri probiotic vs placebo for 8 weeks, on top of usual treatment
What it measured
Several kinds of outcomes
How long
8 weeks
Who has a stake
No stake declared
No competing interests declared.
Journal
Brain, behavior, and immunity, 2025
Source
PubMed record 40484149. This page is based on the abstract only.

How much this study counts

  • ✓Randomized: people were put into groups by chance, so the groups start out alike.
  • ✓Compared with a placebo, a dummy treatment.
  • •Medium size: 75 people.
  • –Short: 8 weeks. Longer-term effects are unknown.
  • •Measured several kinds of outcomes.
  • ✓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

Each dot is one on-topic paper on this question. Steps near the top answer the question more directly.

↑ 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

    ↑ This study is the ringed dot

  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

Of the other 9 papers on the same step: 4 benefit, 2 mixed, 3 no difference. This one found no difference.

Other papers on the same step

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 reviewer corrected 2 fields after reading the abstract. 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
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