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Bacteroidetes Neurotoxins and Inflammatory Neurodegeneration
Zhao Y, Lukiw WJ.. Molecular neurobiology, 2018-04-10
Topic: Brain proteins, microglia and lab models
The gram-negative facultative anaerobe Bacteroides fragilis (B. fragilis) constitutes an appreciable proportion of the human gastrointestinal (GI)-tract microbiome. As is typical of most gram-negative bacilli, B. fragilis secretes an unusually complex mixture of neurotoxins including the extremely pro-inflammatory lipopolysaccharide BF-LPS. LPS (i) has recently been shown to associate with the periphery of neuronal nuclei in sporadic Alzheimer's disease (AD) brain and (ii) promotes the generation of the inflammatory transcription factor NF-kB (p50/p65 complex) in human neuronal-glial cells in primary-culture.
Key findings
- As is typical of most gram-negative bacilli, B. fragilis secretes an unusually complex mixture of neurotoxins including the extremely pro-inflammatory lipopolysaccharide BF-LPS.
- LPS (i) has recently been shown to associate with the periphery of neuronal nuclei in sporadic Alzheimer's disease (AD) brain and (ii) promotes the generation of the inflammatory transcription factor NF-kB (p50/p65 complex) in human neuronal-glial cells in primary-culture.
- In turn, the NF-kB (p50/p65 complex) strongly induces the transcription of a small family of pro-inflammatory microRNAs (miRNAs) including miRNA-9, miRNA-34a, miRNA-125b, miRNA-146a, and miRNA-155.
- These ultimately bind with the 3'-untranslated region (3'-UTR) of several target messenger RNAs (mRNAs) and thereby reduce their expression.
Why it matters
This paper describes how a neurotoxin from a gut bacterium, Bacteroides fragilis, may promote inflammatory neurodegeneration and has been found in Alzheimer's disease brain tissue. It is a mechanistic and observational report, not a trial, so it does not show that targeting this bacterium treats or prevents the disease.
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Study details
- Evidence strengthLow
How this study scored 43/100
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 (Molecular neurobiology) |
| Journal's citation record | 2 / 4 | Molecular Neurobiology: journal h-index 176 (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 | 2018 — 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 127 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 12.7 citations a year over 10 year(s) since 2018 |
| Impact for its field and year | 3 / 6 | Cited 4.4× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 2 / 4 | Cited 48 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Walter J. Lukiw: h-index 75 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Louisiana State University: institution h-index 856 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 29637444) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 43 / 100 | — |
What each of these 20 components measures, and what this score is not →
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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
Zhao, Y., & Lukiw, W. J. (2018). Bacteroidetes Neurotoxins and Inflammatory Neurodegeneration. Molecular neurobiology. https://doi.org/10.1007/s12035-018-1015-y
Vancouver
Zhao Y, Lukiw WJ. Bacteroidetes Neurotoxins and Inflammatory Neurodegeneration. Molecular neurobiology. 2018. doi:10.1007/s12035-018-1015-y. PMID: 29637444.
BibTeX
@article{zhao2018-29637444,
author = {Zhao, Y. and Lukiw, W. J.},
title = {{Bacteroidetes Neurotoxins and Inflammatory Neurodegeneration}},
journal = {Molecular neurobiology},
year = {2018},
doi = {10.1007/s12035-018-1015-y},
pmid = {29637444},
url = {https://doi.org/10.1007/s12035-018-1015-y}
}
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