probiome Sign in
← Conditions Mental health Genus-level

Depression

Compared within 2 studies that had both: 65 people with depression and 56 healthy people. No genera less common in people with depression, and none more common.

A difference is an association: it doesn’t mean these genera cause, prevent or treat depression. GMrepo reports this group at the genus level only, so these are genera, not species.

Searching opens both lists and shows only matching rows.

Less common in depression · 0

Strongest first, then the biggest gap · Each figure is 10 people Strongest first · Each figure is 10 people

None compared.

More common in depression · 0

Strongest first, then the biggest gap · Each figure is 10 people Strongest first · Each figure is 10 people

None compared.

As many carry these · 1 the amount differs

Strongest first, then the biggest gap · Each figure is 10 people Strongest first · Each figure is 10 people
  1. Bacteroides genus in 2 studies Healthy 100% depression 100%

    Carriers have about half as much, in 2 of 2 studies (12% → 6.8% of their gut microbes).

Where these numbers come from

Studies
Only GMrepo projects that had people with the condition and healthy people, 10 or more of each. Numbers come from those studies, never from pooling.Sampled in China.
How common
The share of people whose sample has any of it, in the people with the condition and in the healthy people of those same studies. Tested within studies (Cochran–Mantel–Haenszel, corrected for testing many microbes); a difference counts when it is clear and meaningful (Cohen’s h of 0.2 or more).
Strength word
Counted by code from how many studies point the same way: Seen again and again (3 or more, none clearly the other way), Seen more than once (2, the majority), Seen once (1, listed last). Where studies disagree, a row isn’t listed.
Each study
Tap a row for every study’s own numbers, and for how much carriers have.
Analysis
Our analysis of GMrepo data. GMrepo on Data sources · Read the rules

Also compared · 86 genera

Compared within studies that had both, but not listed above.

Studies disagree · 1

  • Gemella fewer in 1 · more in 1 · 2 studies

No meaningful difference · 85
PubMed · human studies and reviews first

Recent research

All research on it
  1. Randomized trial Experimental and clinical psychopharmacology · 2026
    Effects of Bifidobacterium longum 1714 on low mood and related symptoms: A randomized, double-blind, placebo-controlled trial.
    PubMed ↗
  2. Observational Phytomedicine · 2026
    Zuojin Pill ameliorates depression with gastrointestinal dysfunction via Parabacteroides distasonis.
    PubMed ↗
  3. Randomized trial Scientific reports · 2026
    A study on the efficacy and safety of fecal microbiota transplantation as an adjunctive therapy for treating depressive episodes.
    PubMed ↗
  4. Randomized trial BMC complementary medicine and therapies · 2025
    The effect of probiotics on anxiety, depression, nicotine dependence, and metabolic biomarkers in smokers: a randomized clinical trial.
    PubMed ↗
  5. Systematic review European journal of gastroenterology & hepatology · 2025
    Comparative effectiveness and safety of probiotics with psychotropic potential in mental health benefits in irritable bowel syndrome: a systematic review and network meta-analysis.
    PubMed ↗

Source: PubMed, U.S. National Library of Medicine · 155 linked papers, last 10 years