MetaBiom
Microbiome & Chronic Diseases

Evidence Based Medicine

Alzheimer's disease {40000139}

Record Keys


Definition:
Alzheimer's disease
Class:[  ]

Details


Other Terms:
AD, ASD
Authoring date:
2020-09-06

Links


Meta Information


ICD:[  ]
Category:
Neurologic
MedDra ID:
10012271
MedDra Level:
pt

Notes


[  ]

Shared Notes


  • [1.8
    - Fungi in gut linked to higher Alzheimers risk can be reduced through ketogenic diet.
  • [1.9
    - The gut microbiota-derived metabolite TMAO is elevated in the CSF of individuals with MCI and AD dementia, and that levels of CSF TMAO are associated with CSF biomarkers of AD pathology and neuronal degeneration.
  • [1.10
    - AD elders were also depleted in Adlercreutzia equolifaciens, an equol-producing bacterium, which has beneficial effects in reducing experimental cutaneous inflammation in mice and the loss of which has been associated with the neurodegenerative disorder multiple sclerosis.
    - Bacteroides vulgatushe is a predictor of AD dementia which cause inflammatory states.
    - Increased proportions of Bacteroides, Alistipes, Odoribacter, and Barnesiella and decreased proportions of Lachnoclostridium were present in AD elders.
    - Increased proportions of Odoribacter and Barnesiella and decreased proportions of Eubacterium , Roseburia , Lachnoclostridium and Collinsella were seen in elders with other dementia types.
  • [1.11
    - The gut microbiome of AD participants has decreased microbial diversity.
    - Bacteroidetes are increased and Bifidobacterium and Firmicutes are decreased in the microbiome of AD participants.
    - Porphyromonas gingivalis, the keystone pathogen in chronic periodontitis, identified in the brain of Alzheimers disease patients. Toxic proteases from the bacterium called gingipains were also identified in the brain of Alzheimes patients, and levels correlated with tau and ubiquitin pathology.
    - Oral infections with Porphyromonas gingivalis, or introduction of its lipopolysaccharide (LPS), in various mouse models has demonstrated the development of key neuropathological hallmark lesions defining AD.
  • [1.12
    - AD elders had increased proportions of specific bacterial species that have associations with neurological disorders (including AD). These include Odoribacter splanchnicus, a bacterial species with genes that have been associated with the Alzheimers pathway (5)
    - Blautia were more abundant in AD patients.
    - Elevated GABA was potentially associated with a lower risk of AD.
    - Gut microbial neurotransmitter GABA, a downstream product of Blautia-dependent arginine metabolism, was related to a reduced risk of AD.
    - Lower levels of gut product of GABA were observed in patients with AD.
    - The biological mechanisms of GABA production include degradation of putrescine, decarboxylation of glutamate, or from arginine or ornithine. In
    - Blautia has a strong correlation with arginine metabolism, which may be involved in AD pathogenesis by regulating its downstream products such as GABA, supporting the potential pathway.
    - Elevated Enterobacteriales was also associated with a higher risk of ASD.
    - Gut microbiome may excrete large quantities of lipopolysaccharides and amyloids, resulting in the pathogenesis of AD during aging when the permeability of gastrointestinal tract epithelium or blood-brain barrier increases.
  • [1.13
    - At the follow-up visit 2 months post-FMT, the patient’s wife reported improvements in the patient’s mental acuity and affect. The MMSE was re-administered by the gastroenterologist (and subsequently by the neurologist) and the patient scored 26, indicating normal cognition. Four months post-FMT, the patient reported continued improvement in memory, with no progression in symptoms. The patient now remembered his daughter’s birthday, which he had not been able to recall previously, and was able to correct the physician’s recollections of his symptoms. Six months post-FMT, the patient reported a marked improvement in mood, was more interactive, and showed more expressive affect.
  • [1.14
    - Amyloid SUVR uptake is positively associated with
    - blood LPS
    - acetate and valerate
    - pro-inflammatory cytokines
    - biomarkers of endothelial dysfunction
    - Amyloid SUVR uptake is is negatively correlated with
    - butyrate
    - anti-inflammatory cytokine IL10
    -Endothelial dysfunction is positively associated with
    - pro-inflammatory cytokines, acetate and valerate
    -Endothelial dysfunction is negatively associated with
    - butyrate and IL10 levels.
  • [1.15
    - Curli are cell surface amyloid proteins abundantly expressed by E. coli to exacerbate αSyn-induced behavioral deficits, including intestinal and motor impairments.
  • [1.16
    - Porphyromonas gingivalis, the keystone pathogen in chronic periodontitis, was identified in the brain of Alzheimer’s disease patients. Toxic proteases from the bacterium called gingipains were also identified in the brain of Alzheimer’s patients, and levels correlated with tau and ubiquitin pathology.
  • [1.17
    - Resveratrol has been proposed as a beneficial compound to delay ageing and cellular senescence.
  • [1.4
    - Bifidobacterium breve, improves cognition.
    - The improvement of cognitive function reveal an inverse correlation of HbA1c with total RBANS score amelioration after the study only in the probiotic group.
  • [1.18
    - Increasing evidence points to several mitochondrial functions that are affected in AD.
    - Deficit in this mitochondrial may be at the heart of the progression of AD itself.
  • [1.19
    - Various gut microbes such as Actinobacteria, Bacteroidetes, E. coli, Firmicutes, Proteobacteria, Tenericutes, and Verrucomicrobia are known to play a crucial role in the pathogenesis of AD.
    - These microbes and their metabolites modulate various physiological processes that contribute to AD pathogenesis, such as neuroinflammation and other inflammatory processes, amyloid deposition, cytokine storm syndrome, altered BDNF and NMDA signaling, impairing neurodevelopmental processes.
    - Epigenetic markers associated with AD mainly include histone modifications and DNA methylation, which are under the direct control of a variety of enzymes, such as acetylases and methylases which activity is dependent upon the metabolites generated by the host’s gut microbiome.
  • [1.7
    - At genera and species levels, higher subgingival periodontal dysbiosis was associated with reduced CSF amyloid beta (Aβ)42 but not with P‐tau.

Common References