Psen1 expression was regulated in experimental gut inflammation and in patients with IBD. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Research
27,780 Alzheimer's and dementia studies in plain English, each scored out of 100.
Microbes have inhabited the earth for hundreds of millions of years longer than humans. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
43/100
This review explores the molecular processes underlying MGBA interactions, including vagus nerve signaling, systemic immunological responses, and metabolites produced by microorganisms. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
One of the most challenging and controversial issues in microbiome research is related to gut microbial metabolism and neuropsychological disorders. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
JOURNAL/nrgr/04.03/01300535-202410000-00029/figure1/v/2024-02-06T055622Z/r/image-tiff Disturbances in the microbiota-gut-brain axis may contribute to the development of Alzheimer's disease. 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The human oral microbiome can affect brain functions directly through the trigeminal nerve and olfactory system and indirectly via the oral-gut-brain axis. 5 key findings →
Design: narrative review Evidence: low
Full summary, score breakdown and related studies → Original source
The microbiota-gut-brain axis (MGBA) is increasingly recognized as a critical regulator of brain health, influencing both neurodevelopment and age-related neurological decline. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The complex interrelation of gut microbiota with human health underlines the profound influence this microbial ecosystem has on mechanisms of disease and wellness. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Alzheimer's disease (AD) is the most prevalent type of dementia, but its etiopathogenesis is not yet fully understood. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
The hallmarks of Alzheimer's disease (AD) include brain dysfunction and the buildup of amyloid and tau proteins. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
43/100
The gastrointestinal (GI) tract, home to the largest microbial population in the human body, plays a crucial role in overall health through various mechanisms. 4 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with limited treatment options, underscoring the need for novel therapeutic targets. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Alzheimer's disease (AD) is increasingly recognized as a condition shaped not only by central nervous system pathology but also by complex, bidirectional interactions between the gut, brain, and immune system. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Trillions of microbes live symbiotically in the host, specifically in mucosal tissues such as the gut. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Neurodegenerative diseases are caused by the loss of neurons and/or their myelin sheaths, which deteriorate over time and become dysfunctional. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
An essential regulator of neurodegenerative conditions like Alzheimer's disease (AD) is the gut microbiota. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The gut-brain axis plays a critical role in maintaining neuronal integrity and influencing the progression of Alzheimer's disease (AD). 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Disturbances in the local and peripheral immune systems are closely linked to a wide range of diseases. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Recent studies increasingly highlight the complex interaction between gut microbiota and mental health, drawing attention to the role of the microbiota-gut-brain axis (MGBA) in the pathophysiology of mental and neurodevelopmental disorders. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
Neurodegenerative diseases are severe, age-related conditions with complex etiologies that result in significant morbidity and mortality. 4 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Regulating the gut flora ecological balance upregulates neurotrophic factor expression, regulates the microbiota-gut-brain (MGB) axis, and suppresses the inflammatory responses. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Arteriosclerotic cerebral small vessel disease (aCSVD) is a major cause of stroke and dementia. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
43/100
In both cohorts, few differences between the control and AD groups were observed in terms of alpha and beta diversities, phyla and genera proportions. 5 key findings →
Evidence: moderate
Full summary, score breakdown and related studies → Original source
The gut microbiota, consisting of trillions of microorganisms, plays a critical role in regulating host physiology, including metabolism, immune responses, and brain function. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
The gut microbiota plays a crucial role in the pathogenesis of AD through continuous bidirectional communication via the microbiota-gut-brain axis. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
From across this tag
9 of the 273 studies in this tag, picked by a fixed rule (a hash of each study's address), not by score or date; each page of this list shows a different 9. The same 9 appear here every time.
- Porphyromonas gingivalis in Alzheimer's disease brains: Evidence for disease causation and treatment with small-molecule inhibitors
- Protective effects of Akkermansia muciniphila on cognitive deficits and amyloid pathology in a mouse model of Alzheimer's disease
- The role of gut microbiota in pathogenesis of Alzheimer's disease
- The Gut-Brain Axis: How Microbiota and Host Inflammasome Influence Brain Physiology and Pathology
- Prebiotic Effect of Fructooligosaccharides from Morinda officinalis on Alzheimer's Disease in Rodent Models by Targeting the Microbiota-Gut-Brain Axis
- Gut microbiota mediates the association between aging and cognitive function: evidence from a population-based Kyotango study linking diet, Bifidobacterium, and Mini-Mental State Examination (MMSE) score
- Exercise and probiotics attenuate the development of Alzheimer's disease in transgenic mice: Role of microbiome
- Structural and Functional Dysbiosis of Fecal Microbiota in Chinese Patients With Alzheimer's Disease
- The Multinutrient Fortasyn Connect Influences Gut Microbiota and Intestinal Function in Early Alzheimer's Disease
Where “Free full text” comes from
Free full text links and the Full text may need a subscription label come from Unpaywall, Europe PMC and OpenAlex records of free copies, checked 10 Oct 2026. A study with neither is unknown, not paywalled. Show only studies that are free to read
How the 0–100 score works — and why some entries are capped
This is alzhub's own score. It is not an official metric, not an impact factor, and no journal, publisher or ranking body endorses it. We built it so that a reader who is not a scientist can tell a landmark trial from a conference abstract without having to already know the difference. Every point comes from one of 20 components, all of them printed on the study itself, so you can disagree with our arithmetic rather than having to trust the total.
- Journal tier up to 10 pts
- Journal's citation record up to 4 pts
- Study design up to 12 pts
- Strength of evidence up to 5 pts
- Peer-review validation up to 10 pts
- How recent up to 5 pts
- Sample size up to 4 pts
- Effect reported up to 3 pts
- Studied in people up to 3 pts
- Randomised / blinded up to 2 pts
- Times cited up to 7 pts
- Citations per year up to 5 pts
- Impact for its field and year up to 6 pts
- Cited by studies here up to 6 pts
- Still being cited up to 4 pts
- Senior author's track record up to 4 pts
- Institution's track record up to 3 pts
- Multi-centre collaboration up to 3 pts
- Indexed in PubMed up to 2 pts
- Free to read up to 2 pts
Journals are placed in ordered tiers, never given a numeric impact factor — we could not verify current impact factors from a source we control, and an invented one would be worse than none. Tier 1 is the top-tier general journals (NEJM, The Lancet, JAMA, Nature, Science, Nature Medicine); tier 2 is the leading specialty journals; tier 3 is every other peer-reviewed journal. A separate part scores how much the journal's own papers are cited, which tells the tier-3 journals apart.
Two rules we don't bend. First, we never fill in a missing value: if a record does not state a sample size or a design, that component scores zero, and if we simply have no data for a part, such as a citation count, that part is left out and the study is scored on the parts we could check. The study card says which. Second, anything that is not a peer-reviewed article is capped at 16/100 and carries a warning chip — so a conference abstract or a company press release can never outrank a peer-reviewed paper, no matter how good it looks.
We rank a rigorous null result — a good trial showing that something does not work — above an early positive finding. Someone deciding whether to buy a supplement is served by that, and the rigour is already counted by the design and journal components.
The score is computed from the published data alone and is reproducible: the same file always yields the same numbers.
See the whole rubric drawn out → — four charts covering all 27,780 studies: how the scores are spread and where the cap bites, which of the 20 components the library is strong and weak on, which subjects rest on stronger evidence, and what kinds of study each subject is actually built from.
What this library is — and isn't
This is a large sample of the Alzheimer's literature, not an exhaustive index of it. It holds 27,780 records, built mostly from automated pulls of Europe PMC (61.1% of the library) and OpenAlex (18.3%), plus smaller pulls from PubMed, Crossref and medRxiv. If a study, a drug, or a finding isn't here, that is not evidence it doesn't exist in the literature — it may simply not have been pulled in yet.
1,034 records (3.7% of the library) are not peer-reviewed — 962 of those are preprints posted before any journal review, and the rest are conference abstracts, regulatory notices and reports. Every study card on this page states its status plainly, and the score above is capped for anything that isn't a peer-reviewed article.
See the full, machine-readable breakdown of this library's coverage →