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The growing link between microbes, mood and mental health
Tim Vernimmen. Knowable Magazine, 2024-01-09
Topic: Risk, prevention and care in population studies
Most remarkably, research by Cryan and others has shown that transplanting microbes from the guts of people with psychiatric disorders like depression to the guts of rodents can cause comparable symptoms in the animals.CREDIT: JAMES PROVOST (CC BY-ND)Neuroscientist John CryanUniversity College CorkThese effects may occur in several ways — through the vagus nerve connecting the gut to the brain, through the influence of gut bacteria on our immune systems, or by microbes synthesizing molecules that our nerve cells use to communicate. Many psychiatric disorders are also known to be associated with various gastrointestinal issues, though cause and effect often aren’t clear yet. Food & Environment Blessed are the (tiny) cheesemakers The next part of the puzzle came when we showed that mice born in a germ-free environment have an exaggerated stress response when they grow up. So we’d already shown that stress was affecting the microbiome, and now we’d shown that the microbiome is regulating how a mouse responds to stress. This can be done by transplanting the microbes from a mouse model for a psychiatric disease to a healthy mouse to see whether that creates similar issues, or vice versa, to see if it can resolve them.Following a similar logic, we have shown that the microbiome can be important in brain aging and cognitive decline. They also performed significantly better in mazes designed to test their memory. If you look at the beige, bland food served in many nursing homes and hospitals today, that is not the kind of diet that helps people to maintain a healthy microbiome and therefore a healthy brain.“Perhaps if you’re thinking of having a midlife crisis, forget about the motorbike and start growing vegetables.”— JOHN CRYANWe’ve done a study in mice where we adjusted their diet to contain much more inulin, a fiber that we know supports the growth of beneficial bacterial strains, and found we could dampen down the neuroinflammation that is often associated with cognitive decline in aging. An earlier study of ours showed that students born by C-section, who missed out on some of the microbes that newborns acquire during vaginal birth, had an elevated immune and psychological response to both chronic and acute stress, in line with our findings in mice. It would be very interesting to test if a psychobiotic diet might benefit them.As I said, many psychiatric disorders are also associated with inflammation and other problems in the gut. Of course, this relationsh
Key findings
- Most remarkably, research by Cryan and others has shown that transplanting microbes from the guts of people with psychiatric disorders like depression to the guts of rodents can cause comparable symptoms in the animals.CREDIT: JAMES PROVOST (CC BY-ND)Neuroscientist John CryanUniversity College CorkThese effects may occur in several ways — through the vagus nerve connecting the gut to the brain, through the influence of gut bacteria on our immune systems, or by microbes synthesizing molecules that our nerve cells use to communicate.
- Many psychiatric disorders are also known to be associated with various gastrointestinal issues, though cause and effect often aren’t clear yet.
- Food & Environment Blessed are the (tiny) cheesemakers The next part of the puzzle came when we showed that mice born in a germ-free environment have an exaggerated stress response when they grow up.
- So we’d already shown that stress was affecting the microbiome, and now we’d shown that the microbiome is regulating how a mouse responds to stress.
- This can be done by transplanting the microbes from a mouse model for a psychiatric disease to a healthy mouse to see whether that creates similar issues, or vice versa, to see if it can resolve them.Following a similar logic, we have shown that the microbiome can be important in brain aging and cognitive decline.
Why it matters
This article describes research in rodents linking gut microbes to stress, psychiatric symptoms, and brain aging, with cause and effect in humans still unclear. It is early animal work and does not establish any treatment, cure, or prevention for Alzheimer's disease.
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Study details
- Evidence strengthHigh
How this study scored 30/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it. We have no data on institution's track record, so that was left out: it earned 29 of the 97 points we could judge it on, which is 30 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Knowable Magazine) |
| Journal's citation record | 0 / 4 | Knowable Magazine: journal h-index 6 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2024 — within 3 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 0 / 7 | Cited 0 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.0 citations a year over 4 year(s) since 2024 |
| Impact for its field and year | 0 / 6 | Cited 0.0× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 0 / 4 | Last-listed author Tim Vernimmen: h-index 2 (OpenAlex, whole career) |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 0 institution(s) in 0 countries — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 2 / 2 | Free to read |
| Points | 29 / 97 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 29 of the 97 points we could judge it on is 30 out of 100. |
| Total | 30 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Vernimmen, T. (2024). The growing link between microbes, mood and mental health. Knowable Magazine. https://doi.org/10.1146/knowable-010924-1
Vancouver
Vernimmen T. The growing link between microbes, mood and mental health. Knowable Magazine. 2024. doi:10.1146/knowable-010924-1.
BibTeX
@article{vernimmen2024-e8066f46,
author = {Vernimmen, Tim},
title = {{The growing link between microbes, mood and mental health}},
journal = {Knowable Magazine},
year = {2024},
doi = {10.1146/knowable-010924-1},
url = {https://doi.org/10.1146/knowable-010924-1}
}