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Analysis of the relationship between the gut microbiome and dementia: a cross-sectional study conducted in Japan
Saji N, Niida S, Murotani K, Hisada T, Tsuduki T, Sugimoto T, Kimura A, Toba K et al.. Scientific reports, 2019-01-30
Topic: Risk, prevention and care in population studies
Dysregulation of the gut microbiome is associated with several life-threatening conditions and thus might represent a useful target for the prevention of dementia. However, the relationship between the gut microbial population and dementia has not yet been fully clarified. We recruited outpatients visiting our memory clinic to participate in this study. Information on patient demographics, risk factors, and activities of daily living was collected, and cognitive function was assessed using neuropsychological tests and brain magnetic resonance imaging scans. Faecal samples were obtained, and the gut microbiome was assessed by terminal restriction fragment length polymorphism (T-RFLP) analysis, one of the most well-established and reliable 16S ribosomal RNA-based methods for classifying gut microbiota. Patients were divided into two groups, demented and non-demented. Multivariable logistic regression models were used to identify the variables independently associated with dementia. The T-RFLP analysis revealed differences in the composition of the gut microbiome: the number of Bacteroides (enterotype I) was lower and the number of 'other' bacteria (enterotype III) was higher in demented than non-demented patients. Multivariable analyses showed that the populations of enterotype I and enterotype III bacteria were strongly associated with dementia, independent of the traditional dementia biomarkers. Further studies of the metabolites of gut microbes are needed to determine the mechanism underlying this association.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Saji, N., Niida, S., Murotani, K., Hisada, T., Tsuduki, T., Sugimoto, T., et al. (2019). Analysis of the relationship between the gut microbiome and dementia: a cross-sectional study conducted in Japan. Scientific reports. https://doi.org/10.1038/s41598-018-38218-7
Vancouver
Saji N, Niida S, Murotani K, Hisada T, Tsuduki T, Sugimoto T, et al. Analysis of the relationship between the gut microbiome and dementia: a cross-sectional study conducted in Japan. Scientific reports. 2019. doi:10.1038/s41598-018-38218-7. PMID: 30700769.
BibTeX
@article{saji2019-30700769,
author = {Saji, N. and Niida, S. and Murotani, K. and Hisada, T. and Tsuduki, T. and Sugimoto, T. and Kimura, A. and Toba, K. and others},
title = {{Analysis of the relationship between the gut microbiome and dementia: a cross-sectional study conducted in Japan}},
journal = {Scientific reports},
year = {2019},
doi = {10.1038/s41598-018-38218-7},
pmid = {30700769},
url = {https://doi.org/10.1038/s41598-018-38218-7}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
Key findings
- Dysregulation of the gut microbiome is associated with several life-threatening conditions and thus might represent a useful target for the prevention of dementia.
- Multivariable logistic regression models were used to identify the variables independently associated with dementia.
- The T-RFLP analysis revealed differences in the composition of the gut microbiome: the number of Bacteroides (enterotype I) was lower and the number of 'other' bacteria (enterotype III) was higher in demented than non-demented patients.
- Multivariable analyses showed that the populations of enterotype I and enterotype III bacteria were strongly associated with dementia, independent of the traditional dementia biomarkers.
Why it matters
This cross-sectional study found that the gut microbiome composition differed between demented and non-demented patients, with lower Bacteroides and higher 'other' bacteria in the demented group. Because it is cross-sectional, it cannot show whether these microbiome differences cause dementia or result from it.
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Study details
- Evidence strengthLow
How this study scored 50/100
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.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Scientific reports) |
| Journal's citation record | 3 / 4 | Scientific Reports: journal h-index 463 (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 | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2019 — within 10 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 | 5 / 7 | Cited 222 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 24.7 citations a year over 9 year(s) since 2019 |
| Impact for its field and year | 4 / 6 | Cited 8.9× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 5 other studies in this library |
| Still being cited | 3 / 4 | Cited 69 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Takashi Sakurai: h-index 45 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Tohoku University: institution h-index 880 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 5 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 30700769) |
| Free to read | 2 / 2 | Free to read |
| Total | 50 / 100 | — |
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Read the original
- DOI: 10.1038/s41598-018-38218-7
- PubMed: 30700769
- Original source →
- Free full text: Scientific Reports →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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