Gut Microbiota and Dysbiosis in Alzheimer’s Disease: Implications for Pathogenesis and Treatment

Liu, Shan; Gao, Jiguo; Zhu, Mingqin; Liu, Kangding; Zhang, Hong‐Liang

doi:10.1007/s12035-020-02073-3

Cited by 284 publications

(211 citation statements)

References 172 publications

(213 reference statements)

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“…Several environmental factors, including antibiotic and antifungal treatments, can cause the development of a dysbiotic state within these communities [ 127 , 128 ]. Mounting evidence indicates that gut dysbiosis may promote Aβ aggregation and neuroinflammation in AD development [ 129 ]. Broad-spectrum antimicrobials can be thus “two-edged swords”.…”

Section: Discussionmentioning

confidence: 99%

Multi-pathogen infections and Alzheimer’s disease

et al. 2021

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Alzheimer’s disease (AD) is a chronic neurodegenerative disease associated with the overproduction and accumulation of amyloid-β peptide and hyperphosphorylation of tau proteins in the brain. Despite extensive research on the amyloid-based mechanism of AD pathogenesis, the underlying cause of AD is not fully understood. No disease-modifying therapies currently exist, and numerous clinical trials have failed to demonstrate any benefits. The recent discovery that the amyloid-β peptide has antimicrobial activities supports the possibility of an infectious aetiology of AD and suggests that amyloid-β plaque formation might be induced by infection. AD patients have a weakened blood–brain barrier and immune system and are thus at elevated risk of microbial infections. Such infections can cause chronic neuroinflammation, production of the antimicrobial amyloid-β peptide, and neurodegeneration. Various pathogens, including viruses, bacteria, fungi, and parasites have been associated with AD. Most research in this area has focused on individual pathogens, with herpesviruses and periodontal bacteria being most frequently implicated. The purpose of this review is to highlight the potential role of multi-pathogen infections in AD. Recognition of the potential coexistence of multiple pathogens and biofilms in AD’s aetiology may stimulate the development of novel approaches to its diagnosis and treatment. Multiple diagnostic tests could be applied simultaneously to detect major pathogens, followed by anti-microbial treatment using antiviral, antibacterial, antifungal, and anti-biofilm agents.

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Section: Discussionmentioning

confidence: 99%

Multi-pathogen infections and Alzheimer’s disease

et al. 2021

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“…SCFA, bile acids, trimethylamine-N-oxide, and immunoglobulin A produced by the gut microbiome act as metabolic modulators [ 76 ]. Gut microbiota directly activate the vagus nerve from the enteric nervous system to transmit the signals from the gut to the brain [ 77 ]. The activation of the HPA axis releases cortisol from the adrenal gland that influences gut microbiota composition and survival, which, in turn regulates the host immune response and other types of metabolism [ 77 ].…”

Section: Improvement Of the Gut–liver–brain Axis By Chungkookjangmentioning

confidence: 99%

γ-PGA-Rich Chungkookjang, Short-Term Fermented Soybeans: Prevents Memory Impairment by Modulating Brain Insulin Sensitivity, Neuro-Inflammation, and the Gut–Microbiome–Brain Axis

Jeong¹,

Ryu²,

Yang³

et al. 2021

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Fermented soybean paste is an indigenous food for use in cooking in East and Southeast Asia. Korea developed and used its traditional fermented foods two thousand years ago. Chungkookjang has unique characteristics such as short-term fermentation (24–72 h) without salt, and fermentation mostly with Bacilli. Traditionally fermented chungkookjang (TFC) is whole cooked soybeans that are fermented predominantly by Bacillus species. However, Bacillus species are different in the environment according to the regions and seasons due to the specific bacteria. Bacillus species differently contribute to the bioactive components of chungkookjang, resulting in different functionalities. In this review, we evaluated the production process of poly-γ-glutamic acid (γ-PGA)-rich chungkookjang fermented with specific Bacillus species and their effects on memory function through the modulation of brain insulin resistance, neuroinflammation, and the gut–microbiome–brain axis. Bacillus species were isolated from the TFC made in Sunchang, Korea, and they included Bacillus (B.) subtilis, B. licheniformis, and B. amyloliquefaciens. Chungkookjang contains isoflavone aglycans, peptides, dietary fiber, γ-PGA, and Bacillus species. Chungkookjangs made with B. licheniformis and B. amyloliquefaciens have higher contents of γ-PGA, and they are more effective for improving glucose metabolism and memory function. Chungkookjang has better efficacy for reducing inflammation and oxidative stress than other fermented soy foods. Insulin sensitivity is improved, not only in systemic organs such as the liver and adipose tissues, but also in the brain. Chungkookjang intake prevents and alleviates memory impairment induced by Alzheimer’s disease and cerebral ischemia. This review suggests that the intake of chungkookjang (20–30 g/day) rich in γ-PGA acts as a synbiotic in humans and promotes memory function by suppressing brain insulin resistance and neuroinflammation and by modulating the gut–microbiome–brain axis.

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“…It is well-known that the composition of gut microbiota can influence the health of distant body organs [ 20 ]. The majority of studies in the past decade have focused on characterizing the complex interactions in the microbiota–gut–brain axis, which are crucial for the maintenance of human psychological and physiological wellbeing and associated with various neuropsychiatric disorders [ 21 , 22 , 23 , 24 ]. Similar to the gut and the brain, a bidirectional relationship also exists between the gut and the kidney.…”

Section: The Importance Of Gut Microbiota In Urinary Tract Infectimentioning

confidence: 99%

The Role of Gut, Vaginal, and Urinary Microbiome in Urinary Tract Infections: From Bench to Bedside

et al. 2020

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The current paradigm of urinary tract infection (UTI) pathogenesis takes into account the contamination of the periurethral space by specific uropathogens residing in the gut, which is followed by urethral colonization and pathogen ascension to the urinary bladder. Consequently, studying the relationship between gut microbiota and the subsequent development of bacteriuria and UTI represents an important field of research. However, the well-established diagnostic and therapeutic paradigm for urinary tract infections (UTIs) has come into question with the discovery of a multifaceted, symbiotic microbiome in the healthy urogenital tract. More specifically, emerging data suggest that vaginal dysbiosis may result in Escherichia coli colonization and prompt recurrent UTIs, while urinary microbiome perturbations may precede the development of UTIs and other pathologic conditions of the urinary system. The question is whether these findings can be exploited for risk reduction and treatment purposes. This review aimed to appraise the three aforementioned specific microbiomes regarding their potential influence on UTI development by focusing on the recent studies in the field and assessing the potential linkages between these different niches, as well as evaluating the state of translational research for novel therapeutic and preventative approaches.

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Gut Microbiota and Dysbiosis in Alzheimer’s Disease: Implications for Pathogenesis and Treatment

Cited by 284 publications

References 172 publications

Multi-pathogen infections and Alzheimer’s disease

Multi-pathogen infections and Alzheimer’s disease

γ-PGA-Rich Chungkookjang, Short-Term Fermented Soybeans: Prevents Memory Impairment by Modulating Brain Insulin Sensitivity, Neuro-Inflammation, and the Gut–Microbiome–Brain Axis

The Role of Gut, Vaginal, and Urinary Microbiome in Urinary Tract Infections: From Bench to Bedside

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