Evidence map›Paper›PMID 33669008›Full record

SynthesisNutrients2021

The Role of Gut Bacterial Metabolites in Brain Development, Aging and Disease.

Shirley Mei-Sin Tran, M Hasan Mohajeri

Open access · goldAbstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Nutrients, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 125 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
125citing papers in PubMed, 4 pooled it
11.8field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

125 citing papers in PubMed, 4 syntheses or guidelines pooled it, 200 citations in OpenAlex.

  1. Recognition of the microbial metaboliteFrontiers in molecular neuroscience · 2025
    Pooled it
  2. Changes in Gut Microbiota and Multiple Sclerosis: A Systematic Review.International journal of environmental research and public health · 2023
    Pooled it
  3. Pooled it
  4. Pooled it
  5. Article
  6. Review
  7. Short-chain fatty acids.Nature metabolism · 2026
    Review
  8. Review
  9. Review
  10. The gut as a central hub for multi-organ crosstalk in aging.Cellular and molecular life sciences : CMLS · 2026
    Review
  11. Comparative Evaluation of Different Fruit Parts ofFoods (Basel, Switzerland) · 2026
    Article
  12. Article
  13. Review
  14. Review
  15. Article
  16. Review
  17. Restoring NADFrontiers in nutrition · 2026
    Review
  18. Review
  19. Review
  20. Article

65 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Shirley Mei-Sin TranDepartment of Medicine, Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
M Hasan MohajeriDepartment of Medicine, Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.ORCID 0000-0002-2112-6281
University of Zurich · CH

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

In the last decade, emerging evidence has reported correlations between the gut microbiome and human health and disease, including those affecting the brain. We performed a systematic assessment of the available literature focusing on gut bacterial metabolites and their associations with diseases of the central nervous system (CNS). The bacterial metabolites short-chain fatty acids (SCFAs) as well as non-SCFAs like amino acid metabolites (AAMs) and bacterial amyloids are described in particular. We found significantly altered SCFA levels in patients with autism spectrum disorder (ASD), affective disorders, multiple sclerosis (MS) and Parkinson's disease (PD). Non-SCFAs yielded less significantly distinct changes in faecal levels of patients and healthy controls, with the majority of findings were derived from urinary and blood samples. Preclinical studies have implicated different bacterial metabolites with potentially beneficial as well as detrimental mechanisms in brain diseases. Examples include immunomodulation and changes in catecholamine production by histone deacetylase inhibition, anti-inflammatory effects through activity on the aryl hydrocarbon receptor and involvement in protein misfolding. Overall, our findings highlight the existence of altered bacterial metabolites in patients across various brain diseases, as well as potential neuroactive effects by which gut-derived SCFAs, p-cresol, indole derivatives and bacterial amyloids could impact disease development and progression. The findings summarized in this review could lead to further insights into the gut-brain-axis and thus into potential diagnostic, therapeutic or preventive strategies in brain diseases.

Indexed as

AgingBrainCentral Nervous System DiseasesFatty Acids, VolatileGastrointestinal MicrobiomeHumansFatty Acids, Volatilebacterial metabolitesgut–brain–axisgut microbiomeSCFAshort-chain fatty acids

Identifiers

PMID33669008
PMCPMC7996516
OpenAlexW3132970311

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.